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of 1. Which the structures below is an aldehyde? O A. CH 3 CH 2CH O B. CH 3 CCH 3 O C. CH 3 CH 2COH O D. CH 3 COCH3 (1) 2. What product results from the reaction of CH2==CH2 with Br2? A. B. C. D. CHBrCHBr CH2CHBr CH3CH2Br CH2BrCH2Br (1) 3. What is the final product formed when CH3CH2OH is refluxed with acidified potassium dichromate(VI)? A. C. D. B. CH3CHO CH2==CH2 CH3COOH HCOOCH3 (1) 4. Two reactions of an alkene, B, are shown below. C 4 H 10 A H2 Ni CH 3 C H B C CH 3 C 4 H 9 Br C H 1 (i) State the name of A and write an equation for its complete combustion. Explain why the incomplete combustion of A is dangerous. ........................................................................................................ ........................................................................................................ ........................................................................................................ ........................................................................................................ ........................................................................................................ (5) (ii) Outline a test to distinguish between A and B, stating the result in each case. ........................................................................................................ ........................................................................................................ ........................................................................................................ ........................................................................................................ (3) (iii) Write an equation for the conversion of B to C. State the type of reaction taking place and draw the structure of C. ........................................................................................................ ........................................................................................................ ........................................................................................................ ........................................................................................................ ........................................................................................................ ........................................................................................................ ........................................................................................................ ........................................................................................................ (3) (Total 11 marks) 2 5. (i) A compound D has the molecular formula C2H4O2 and is obtained from a reaction between methanoic acid and methanol. Write an equation for this reaction and state the name of D. ........................................................................................................ ........................................................................................................ ........................................................................................................ ........................................................................................................ ........................................................................................................ (3) (ii) A second compound, E, has the same molecular formula as D and has acidic properties. State the name of compound E. ........................................................................................................ ........................................................................................................ (1) (Total 4 marks) 6. The first synthetic thread was made from a polyester. A section of the polyester is drawn below: CH2COOCH2COOCH2COO (i) Give the structural formula of the monomer (containing two functional groups) that could be used to make this polyester and state the names of the two functional groups. ........................................................................................................ ........................................................................................................ ........................................................................................................ ........................................................................................................ ........................................................................................................ ........................................................................................................ (3) 3 (ii) State, giving a reason, whether this polyester is made by a condensation reaction or an addition reaction. ........................................................................................................ ........................................................................................................ ........................................................................................................ (2) (Total 5 marks) 7. Which of the substances below is least soluble in water? A. CH2OHCHOHCH2OH O B. CH 3 CCH 3 O C. CH 3 CH 2 COH O D. CH 3 COCH 3 (1) 8. How many different tripeptides can be prepared from three amino acids? (Each amino acid is used only once in a given tripeptide.) A. B. C. D. 1 3 6 9 (1) 9. Which compound reacts fastest with water? A. B. C. D. (CH3)3CBr (CH3)3CCl CH3CH2CH2CH2Br CH3CH2CH2CH2Cl (1) 10. Which of the following compounds exhibits three lines in the 1HNMR spectrum? 4 I. II. III. A. B. C. D. I only CH3CH2OCH (CH3)3 CCl CH3CH2COOH II only I and III only I, II and III (1) 11. (a) Halogenoalkanes undergo nucleophilic substitution reactions. The rates and mechanisms of these reactions depend on whether the halogenoalkane is primary, secondary or tertiary. Explain the term nucleophilic substitution. ...................................................................................................................................... ...................................................................................................................................... ...................................................................................................................................... ...................................................................................................................................... (2) (b) The formula C4H9Br represents more than one compound. Using this formula, draw a structure (showing all bonds between carbon atoms) to represent a halogenoalkane that is (i) primary. (1) (ii) secondary. (1) 5 (iii) tertiary. (1) (Total 5 marks) 12. The stoichiometric equation for a nucleophilic substitution reaction is given below. (CH3)3CBr + OH (CH3)3COH + Br The reaction takes place by means of a two-step mechanism. (i) Write an equation for each step. (2) (ii) Define the following terms. Molecularity ............................................................................................................................ ............................................................................................................................ Rate-determining step ............................................................................................................................ ............................................................................................................................ (2) (iii) Identify the rate-determining step in the mechanism in (i) above. ............................................................................................................................ (1) (Total 5 marks) 6 13. A pleasant-smelling liquid A, was hydrolysed in acid conditions to give two organic products, B and C. Product B, a carboxylic acid, was readily soluble in water. The mass spectrum of B is shown below. 100 90 80 70 60 Relative intensity 50 40 30 20 10 0 20 30 40 50 m/z 60 70 80 (a) (i) Identify the Mr of B. ................................................................................................ (1) (ii) Suggest fragment ions responsible for the peaks at m/z values of 29, 45 and 57. ................................................................................................ ................................................................................................ ................................................................................................ (3) (iii) Using the information in (ii), deduce the structural formula of B. ................................................................................................ ................................................................................................ ................................................................................................ ................................................................................................ (1) 7 (b) Product C was also soluble in water and on analysis was found to contain 60.0 % C, 13.3 % H and 26.7 % O by mass. The Mr of compound C is 60. (i) Calculate the empirical and molecular formulas of C. ................................................................................................ ................................................................................................ ................................................................................................ ................................................................................................ ................................................................................................ ................................................................................................ ................................................................................................ ................................................................................................ (3) (ii) Draw three possible structural formulas for the isomers with this molecular formula. ................................................................................................ ................................................................................................ ................................................................................................ ................................................................................................ ................................................................................................ ................................................................................................ ................................................................................................ ................................................................................................ ................................................................................................ (3) (iii) Explain why two of the isomers in (ii) will show a broad absorption in their infrared spectra which will be missing in the spectrum of the third isomer. ................................................................................................ ................................................................................................ ................................................................................................ (1) 8 (iv) Explain how the two isomers showing the broad absorption in their infrared spectra could be identified from their 1H NMR spectra. ................................................................................................ ................................................................................................ ................................................................................................ ................................................................................................ (2) (c) Compound C was oxidised to compound D by refluxing with acidified sodium dichromate(VI). D was not acidic, but contained the same number of carbon atoms as C. Deduce the structural formulas of C and D and state the name of each one. ........................................................................................................ ........................................................................................................ ........................................................................................................ ........................................................................................................ ........................................................................................................ ........................................................................................................ ........................................................................................................ ........................................................................................................ (4) (d) Deduce the structural formula of A. ........................................................................................................ ........................................................................................................ ........................................................................................................ ........................................................................................................ (1) 9 (e) An alcohol E does not react with acidified potassium dichromate(VI) but forms an alkene, F, with molecular formula C4H8, when heated with concentrated sulfuric acid. (i) Deduce the structures and state the names of E and F. ................................................................................................ ................................................................................................ ................................................................................................ ................................................................................................ ................................................................................................ ................................................................................................ ................................................................................................ ................................................................................................ (4) (ii) Write an equation for the conversion of E to F and state the type of reaction that occurs. ................................................................................................ ................................................................................................ ................................................................................................ (2) (Total 25 marks) 14. A student prepared a sample of compound Y from benzene as follows: C6H6 C6H5CH2CH3 C6H5CHClCH3 X Y (a) (i) The first step was the conversion of benzene to compound X, using chloroethane as the reagent and aluminium chloride as a catalyst. Write the equation for the reaction and give equations for the mechanism. ............................................................................................................................ ............................................................................................................................ (5) 10 (ii) Name the type of mechanism that occurs in the second step when X is converted to Y. ............................................................................................................................ (1) (b) (i) Draw two structures for compound Y, showing the relationship between them. (2) (ii) Explain the term plane-polarized light and describe how the optical isomers of Y could be distinguished using a polarimeter. ............................................................................................................................ ............................................................................................................................ ............................................................................................................................ ............................................................................................................................ ............................................................................................................................ ............................................................................................................................ ............................................................................................................................ ............................................................................................................................ (2) (iii) Explain why the sample of Y produced by the student did not show optical activity. ............................................................................................................................ ............................................................................................................................ ............................................................................................................................ ............................................................................................................................ (4) 11 (c) Samples of compound Y and chlorobenzene are warmed separately with aqueous sodium hydroxide. State, with a reason, whether compound Y or chlorobenzene would react more slowly. ...................................................................................................................................... ...................................................................................................................................... ...................................................................................................................................... ...................................................................................................................................... (2) (Total 16 marks) 15. Which substance(s) could be formed during the incomplete combustion of a hydrocarbon? I. Carbon II. Hydrogen III. Carbon monoxide A. B. C. D. I only I and II only I and III only II and III only (1) 16. Which formulas represent butane or its isomer? I. II. III A. B. C. D. CH3(CH2)2CH3 CH3CH(CH3)CH3 (CH3)3CH I and II only I and III only II and III only I, II and III (1) 12 17. Which compound can exist as optical isomers? A. B. C. D. CH3CHBrCH3 CH2BrCHBrCH3 CH2BrCHBrCH2Br CHBr2CHBrCHBr2 (1) 18. (i) List three characteristics of an homologous series, and explain the term functional group. ........................................................................................................ ........................................................................................................ ........................................................................................................ ........................................................................................................ ........................................................................................................ (3) (ii) Ethanol and ethanoic acid can be distinguished by their melting points. State and explain which of the two compounds will have a higher melting point. ........................................................................................................ ........................................................................................................ ........................................................................................................ ........................................................................................................ (2) (iii) Draw the four different structures of alcohols of formula C4H9OH. Identify the structure that exists as optical isomers and give a reason for your answer. ........................................................................................................ ........................................................................................................ ........................................................................................................ ........................................................................................................ ........................................................................................................ ........................................................................................................ 13 ........................................................................................................ ........................................................................................................ ........................................................................................................ ........................................................................................................ ........................................................................................................ ........................................................................................................ (4) (Total 9 marks) 19. (i) Ethanoic acid reacts with ethanol in the presence of concentrated sulfuric acid and heat. Identify the type of reaction that takes place. Write an equation for the reaction, name the organic product formed and draw its structure. ........................................................................................................ ........................................................................................................ ........................................................................................................ ........................................................................................................ ........................................................................................................ ........................................................................................................ ........................................................................................................ ........................................................................................................ (4) (ii) State and explain the role of sulfuric acid in this reaction. ........................................................................................................ ........................................................................................................ ........................................................................................................ ........................................................................................................ (2) (iii) State one major commercial use of the organic product from this type of reaction. ........................................................................................................ ........................................................................................................ (1) (Total 7 marks) 14 20. For the two compounds HCOOCH2CH3 and HCOOCHCH2: I II (i) State and explain which of the two compounds can react readily with bromine. ........................................................................................................ ........................................................................................................ ........................................................................................................ (2) (ii) Compound II can form polymers. State the type of polymerization compound II undergoes, and draw the structure of the repeating unit of the polymer. (2) (Total 4 marks) 21. (a) (i) Name and describe the mechanism for the reaction between sodium hydroxide solution and 2-bromo-2-methylpropane. Use "curly arrows" to represent the movement of pairs of electrons. ........................................................................................................................... (4) (ii) Predict, giving a reason, how the rate of reaction will be affected if 2-iodo-2-methylpropane is used in place of 2-bromo-2-methylpropane. ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... (2) 15 (b) To confirm that the reaction between 2-bromo-2-methylpropane and sodium hydroxide solution had worked, a student isolated and purified the product. Describe the 1H NMR spectrum of 2-methylpropan-2-ol using TMS (tetramethylsilane) as the reference. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... (3) (Total 9 marks) 22. Explain the following observations. (a) When benzene reacts with bromine in the presence of a catalyst the products are bromobenzene and hydrogen bromide. No addition reaction occurs. (2) ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... (b) The mass spectrum of propan-1-ol shows a peak with a mass to charge ratio of 60 and also a peak at 31. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... (2) 16 (c) There are two isomers of C2H6O. Only one shows a broad infrared absorption at about 3300 cm-1. ...................................................................................................................................... ...................................................................................................................................... ...................................................................................................................................... ...................................................................................................................................... (2) (Total 6 marks) 23. Which is the correct description of the following reaction? C2H4 +H2O C2H5OH A. B. C. D. Addition Condensation Dehydration Hydrogenation (1) 24. Which isomer of C3H6O2 has a 1H NMR spectrum with a different number of peaks from the others? A. B. C. D. HCOOCH2CH3 CH3COOCH3 CH3OCH2CHO CH3CH2COOH (1) 17 25. Which statements support the idea that benzene contains delocalized electrons? I. II. III. A. B. C. D. It undergoes substitution rather than addition reactions. Its enthalpy change of combustion is greater than its enthalpy change of hydrogenation. All its carbon-carbon bonds are the same length. I and II only I and III only II and III only I, II and III (1) 26. Which statement about the reactions of halogenoalkanes with aqueous sodium hydroxide is correct? A. B. C. D. Primary halogenoalkanes react mainly by an S N1 mechanism. Chloroalkanes react faster than iodoalkanes. Tertiary halogenoalkanes react faster than primary halogenoalkanes. The rate of an SN1 reaction depends on the concentration of aqueous sodium hydroxide. (1) 27. Which alkene can be formed by the dehydration of pentan-2-ol? A. B. C. D. CH2CHCH(CH3)2 CH2C(CH3)CH2CH3 CH3CHCHCH3 CH2CH(CH2)2CH3 (1) 18 28. Propene contains a C==C double bond whereas propanal contains a C==O double bond. (a) State and explain two similarities and two differences in the way in which the atoms are bonded in the covalent double bond in the two compounds. Similarities: ................................................................................................................. ...................................................................................................................................... ...................................................................................................................................... ...................................................................................................................................... Differences: ................................................................................................................. ...................................................................................................................................... ...................................................................................................................................... ...................................................................................................................................... (4) (b) Both propene and propanal typically undergo addition reactions. State the type of addition reaction that takes place with each compound. Propene: ....................................................................................................................... Propanal: ...................................................................................................................... (2) (Total 6 marks) 29. (a) Hydrogen cyanide reacts with ethanal to form 2-hydroxypropanenitrile. Describe the mechanism of this reaction using "curly arrows" to show the movement of pairs of electrons. (4) 19 (b) 2-hydroxypropanenitrile can be hydrolyzed under acidic conditions to form 2-hydroxypropanoic acid. (i) Draw the two enantiomers of 2-hydroxypropanoic acid. (2) (ii) State how the two enantiomers differ in their chemical and physical properties. Chemical: ......................................................................................................... ........................................................................................................................... Physical: ........................................................................................................... ........................................................................................................................... (2) (Total 8 marks) 30. Consider the following reaction sequence for the conversion of cyclohexanone into cyclohexene. O OH H 2 SO 4 (a) State the type of reaction taking place when cyclohexanone is converted into cyclohexanol. ...................................................................................................................................... (1) 20 (b) Describe each step in the mechanism (using "curly arrows" to show the movement of pairs of electrons) for the conversion of cyclohexanol to cyclohexene. Explain clearly the two different roles played by the concentrated sulfuric acid in the reaction. ...................................................................................................................................... ...................................................................................................................................... ...................................................................................................................................... (5) (c) Suggest a reason why concentrated phosphoric acid, H3PO4, is usually preferred to concentrated sulfuric acid in the above reaction. ...................................................................................................................................... ...................................................................................................................................... (1) (Total 7 marks) 31. Cyclohexanone can react with 2,4-dinitrophenylhydrazine in aqueous solution. (i) State the type of reaction that takes place. ............................................................................................................................................... (1) (ii) Write a balanced equation for this reaction using structural formulas for the reactants and products. (2) 21 (iii) Explain how the product from this particular reaction can be used to confirm that the reactant was cyclohexanone and not any other carbonyl compound. ................................................................................................................................................ ................................................................................................................................................ (1) (Total 4 marks) 32. Which statement about neighbouring members of all homologous series is correct? A. B. C. D. They have the same empirical formula. They differ by a CH2 group. They possess different functional groups. They differ in their degree of unsaturation. (1) 33. Which type of compound must contain a minimum of three carbon atoms? A. B. C. D. An aldehyde A carboxylic acid An ester A ketone (1) 34. What is the IUPAC name for CH3CH2CH(CH3)2? A. B. C. D. 1,1-dimethylpropane 2-methylbutane isopentane ethyldimethylmethane (1) 22 35. The compound C2H4 can be used as a starting material for the preparation of many substances. (a) Name the compound C2H4 and draw its structural formula. ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... (2) (b) In the scheme below, state the type of reaction and identify the reagent needed for each reaction. A B C2H4 CH3CH2OH CH3COOH ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... (4) (c) C2H4 can be converted into one of the compounds below in a single step reaction. C2H3Cl C2H4Cl2 Draw the structural formula for each of these compounds and identify the compound which can be formed directly from C2H4. ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... (3) 23 (d) One of the two compounds in (c) has an isomer. Draw the structural formula of the isomer and explain why it can not be formed directly from C 2H4. ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... (2) (e) C2H4 can also react to form a polymer. Name this type of polymer and draw the structural formula of a section of this polymer consisting of three repeating units. ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... (2) (f) Polymers can also be formed in a different type of reaction. Identify this type of reaction and name two different types of such polymers. ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... (3) (Total 16 marks) 36. The polymer with the repeating unit H N H C CH 3 O C exists as optical isomers. 24 (i) State a test for optical isomers. ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... (ii) Identify the chiral centre in the repeating unit. ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... (iii) Draw the two enantiomeric forms of the repeating unit. ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... (Total 4 marks) 37. Bromoethane reacts with ammonia as follows. CH3CH2Br + NH3 CH3CH2NH 3 + Br- CH3CH2NH 3 + NH3 CH3CH2NH2 + NH 4 The mechanism for this reaction is described as S N2. 25 (a) State the meaning of each of the symbols in S N2. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... (2) (b) State the name of the organic product of the reaction, CH3CH2NH2. ..................................................................................................................................... (1) (c) Explain, using "curly arrows" to show the movement of electron pairs, the mechanism of the attack by ammoniaon bromoethane, and show the structure of the transition state. (4) (Total 7 marks) 38. The structure of benzene can be represented in two ways. structure A (a) structure B Use information from Table 9 of the Data Booklet to explain why structure B is used instead of structure A. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... (2) 26 (b) The enthalpy changes for the hydrogenation of cyclohexene and benzene are as follows. C6H10 + H2 C6H12 C6H6 + 3H2 C6H12 H = 120 kJ mol1 H = 210 kJ mol1 Explain how this information can be used to support the statement that structure B is more stable than structure A. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... (3) (Total 5 marks) 39. Which compound can exist as optical isomers? A. B. C. D. H2NCH2COOH CH2ClCH2Cl CH3CHBrI HCOOCH3 (1) 40. Which product is formed by the reaction between CH2CH2 and HBr? A. B. C. D. CH3CH2Br CH2CHBr BrCHCHBr CH3CHBr2 (1) 27 41. How many lines are present in the 1H NMR spectrum of C(CH3)4?) A. B. C. D. 1 3 4 12 42. In which of the following ways does benzene, C 6H6, react? I. II. III. A. B. C. D. I only III only I and II only II and III only (1) Combustion Hydrogenation Substitution 43. Which reaction(s) involve(s) the formation of a positive ion? I. II. A. B. C. D. I only II only Both I and II Neither I nor II (1) CH3CH2CH2Br + OH- (CH3)3CBr + OH- 28 44. What is the major product formed when a mixture of CH3CH2OH and concentrated H2SO4 is heated strongly? A. B. C. D. CH3CH3 CH3CH2SO4 CH3COOH CH2CH2 (1) 45. This question refers to the compounds in the following reaction scheme. NaOH C 3 H7 Br A C 3 H8 O B oxidation C 3 H6 O C oxidation C 3 H6 O 2 D (a) The 1HNMR spectra of C and D both show three peaks with area ratios of 3:2:1. The infrared spectra of C and D both show sharp absorptions close to 1720 cm-1. (i) Explain what this spectral information indicates about the structure of C and D, and deduce their structures. ................................................................................................... ................................................................................................... ................................................................................................... ................................................................................................... ................................................................................................... ................................................................................................... ................................................................................................... ................................................................................................... (5) (ii) Suggest two infrared ranges in which there would be absorption in the spectrum of D but not in that of C. ................................................................................................... ................................................................................................... (2) 29 (b) Deduce the structure of B and predict the ratio of areas under the peaks in its 1HNMR spectrum. ......................................................................................................... ......................................................................................................... (2) (c) State a suitable reagent for the oxidation of B to C and C to D. Explain how the oxidation of B to C could be achieved without further oxidation to D. ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... (3) (d) The conversion of A to B takes place by an SN2 mechanism. State what is meant by the term SN2 and describe, by using "curly arrows" to show the movement of electron pairs, the mechanism of this conversion. ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... (6) (e) Deduce how the rate of reaction of A with NaOH would compare with that of the compound CH2CH2CH2Cl with NaOH. Explain your answer by referring to Table 10 of the Data Booklet. ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... (2) 30 (f) B and D react with each other when heated with concentrated sulfuric acid. State the name of this type of reaction and deduce the structure of the product. ......................................................................................................... ......................................................................................................... ......................................................................................................... the ......................................................................................................... (2) (g) Write structure of an ester isomer of D and explain why it is less soluble in water than D. ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... (3) (Total 25 marks) 46. This question is based on the following reaction scheme. C5H10 W (a) C5H11Br X and Y Z C5H12O W has the structure H 3C C H C H CH 2 CH 3 (i) Give the structure of the geometrical isomer of W. (1) 31 (ii) Explain why W has a geometrical isomer. .......................................................................................................................... .......................................................................................................................... .......................................................................................................................... .......................................................................................................................... (2) (iii) State the full name of W. .......................................................................................................................... (2) (b) (i) State the name of the reaction mechanism by which W is converted to X and Y. .......................................................................................................................... (1) (ii) The product Y can exist as optical isomers. Deduce the structure of Y and explain why it shows optical isomerism. .......................................................................................................................... .......................................................................................................................... (2) (iii) Write equations (using "curly arrows" to represent the movement of electron pairs) to show the mechanism of the reaction in which X is formed. (4) 32 (iv) Markovnikov's rule is sometimes useful in predicting the major product in this type of reaction. Explain why this rule cannot be used to predict whether X or Y would be the major product. .......................................................................................................................... .......................................................................................................................... .......................................................................................................................... .......................................................................................................................... (2) (c) The conversion of X to Z involves nucleophilic substitution by an SN1 mechanism. (i) Identify the species responsible for the nucleophilic attack. .......................................................................................................................... (1) (ii) State and explain how the rate of the S N1 reaction for each of the following, using the same nucleophile as in (c)(i), compares with that of X. (CH3)3CBr ...................................................................................................... .......................................................................................................................... .......................................................................................................................... .......................................................................................................................... .......................................................................................................................... (6) C6H5Br .............................................................................................................. .......................................................................................................................... .......................................................................................................................... .......................................................................................................................... .......................................................................................................................... (Total 21 marks) 47. The pKb values of some amines are shown in Table 16 of the Data Booklet. Write an equation for the reaction of ethylamine with water. State and explain how the basicity of ethylamine compares to that of ammonia. ............................................................................................................................................... ............................................................................................................................................... ............................................................................................................................................... ............................................................................................................................................... 33 ............................................................................................................................................... ............................................................................................................................................... ............................................................................................................................................... ............................................................................................................................................... ............................................................................................................................................... (Total 4 marks) 48. Which compound has the lowest boiling point? A. B. C. D. CH3CH2CH(CH3)CH3 (CH3)4C CH3CH2CH2CH2CH3 CH3CH2OCH2CH3 (1) 49. Which species will show optical activity? A. B. C. D. 1-chloropentane 3-chloropentane 1-chloro-2-methylpentane 2-chloro-2-methylpentane (1) 50. What type of reaction does the equation below represent? CH2=CH + Br2 BrCH2CH2Br A. B. C. D. substitution condensation reduction addition (1) 34 51. The alkanes are a homologous series of saturated hydrocarbons. State the meaning of each of the following terms. (i) homologous series ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... (2) (ii) hydrocarbon ..................................................................................................................................... ..................................................................................................................................... (1) (iii) saturated ..................................................................................................................................... ..................................................................................................................................... (1) (Total 4 marks) 52. (a) (i) State and explain the trend in the boiling points of the first five alkanes. ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... (2) (ii) Explain why the enthalpies of combustion of alkanes are negative values. ........................................................................................................................... ........................................................................................................................... (1) 35 (b) State the products of the complete combustion of alkanes. ..................................................................................................................................... ..................................................................................................................................... (2) (Total 5 marks) 53. The plastic PVC, poly(chloroethene), is made from the monomer chloroethene, C 2H3Cl, by a polymerization reaction. (i) Draw the structural formula of chloroethene. ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... (1) (ii) State the type of polymerization reaction that occurs to make poly(chloroethene) and identify the structural feature needed in the monomer. ......................................................................................................... ......................................................................................................... (2) (iii) Draw the structure of the repeating unit of poly(chloroethene). ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... (1) (iv) Explain why monomers are often gases or volatile liquids, whereas polymers are solids. ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... (2) (Total 6 marks) 36 54. Hexanedioic acid and 1,6-diaminohexane react together to form a synthetic polymer. There are many natural polymers, some of the most familiar being proteins formed from 2-amino acids. (i) Give the structural formula of each monomer in the synthetic polymer. ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... (2) (ii) State the type of polymerization reaction that occurs between these two monomers and identify the structural feature needed in the monomers. ......................................................................................................... ......................................................................................................... (2) (iii) Draw the structure of and state the type of linkage formed in this polymer, and identify the other product of this polymerization reaction. ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... (3) 37 (iv) The structures of some 2-amino acids are shown in Table 20 of the Data Booklet. Using alanine as an example, explain what is meant by the term optical activity, identify the structural feature that needs to be present and illustrate your answer with suitable diagrams of both isomers. ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... (3) (v) Identify a 2-amino acid from Table 20 which does not show optical activity. ......................................................................................................... (1) (vi) Polyesters are formed in a similar polymerization reaction to proteins. Their monomers are esters. State one use of esters and identify the two compounds that react together to form the ester ethyl methanoate. ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... (3) (Total 14 marks) 55. Consider the following compounds. I. II. III. CH3CH2CH(OH)CH3 CH3CH(CH3)CH2OH (CH3)3COH 38 The compounds are treated separately with acidified potassium dichromate(VI) solution. Which will produce a colour change from orange to green? A. B. C. D. I and II only I and III only II and III only I, II and III (1) 56. Which compound reacts most rapidly by a SN1 mechanism? A. B. C. D. (CH3)3CCl CH3CH2CH2CH2Br (CH3)3CBr CH3CH2CH2CH2Cl (1) 57. Which compound shows three different environments for hydrogen atoms in the 1H NMR spectrum? A. B. C. D. CH3CH2CH3 CH2OHCH2OH CH3CH2CH2OH CH3CH(OH)CH3 (1) 58. Which statement is correct regarding the structure of benzene? A. B. C. D. The 1H NMR spectrum of benzene shows six different environments for H atoms. Benzene is a symmetrical, planar molecule with three single and three double bonds. The enthalpy change for the hydrogenation of benzene is less exothermic than that of cyclohexatriene. Benzene undergoes addition reactions more readily than substitution reactions. (1) 39 59. X is an organic compound composed of carbon, hydrogen and oxygen, containing 48.63 % carbon and 8.18 % hydrogen by mass. (a) (b) Calculate the empirical formula of X. (4) The mass spectrum for X is shown below. 100 80 60 Relative abundance 40 20 0 0 10 20 30 40 m/z 50 60 70 80 [Source: NIST Mass Spec Data Center, S E Stein, director, "IR and Mass Spectra" in NIST Chemistry WebBook, NIST Standard Reference Database Number 69, Eds. P J Linstrom and W G Mallard, July 2001, National Institute of Standards and Technology, Gaithersburg MD, 20899 (http://webbook.nist.gov)] (i) (ii) Deduce, giving a reason, the molecular formula of X. (2) Identify the formulas of the fragment ions with m/z values of 45 and 29. (2) 40 (c) The infrared spectrum of X is shown below. 100% Transmittance / % 0 4000 3000 2000 1600 1200 800 Wavenumber / cm 1 [Source: NIST Standard Reference Data Program Collect (C) 2003 copyright by the U.S. Secretary of Commerce on behalf of the United States of America. All rights reserved] Using the above spectrum, (i) (ii) (d) explain why X is not a carboxylic acid. (1) identify, giving reasons, three bonds that are present in X. (3) Deduce the most likely structural formula of X based on your answers to (b) and (c). State the name of X and give one use of compounds belonging to this homologous series. (3) (e) State and explain the number of peaks compound X will show in its low resolution 1 H NMR spectrum. (2) (f) State the names of two compounds which could react together to produce X. Identify the type of reaction and give an equation for the reaction. (4) (g) (h) (i) Explain the term isomerism. (1) Give structural formulas for two possible isomers of X. (2) Predict, giving a reason, whether or not you would expect X to be water soluble. (1) (Total 25 marks) 41 60. (a) The manufacture of low-density polyethene uses a free-radical reaction mechanism. (i) State the names of the three steps common to most free-radical mechanisms. ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... (2) (ii) One step in the mechanism can be represented as follows: R3C + CH2==CH2 R3CCH2-CH2 Outline what happens in this step, by reference to the electrons involved. ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... ........................................................................................................................... (2) (b) State the type of mechanism and the catalyst used in the manufacture of high-density polyethene. ..................................................................................................................................... ..................................................................................................................................... (2) (Total 6 marks) 61. The compound methylbenzene, C6H5CH3, was reacted with chlorine under two different conditions. In the presence of aluminium chloride two organic products, F and G, were formed, both with the molecular formula C7H7Cl . Under the other set of conditions three organic products, J, K and L, were formed, with molecular formulas of C7H7Cl, C7H6Cl2 and C7H5Cl3, respectively. 42 (a) Deduce the structures of F and G. F G (2) (b) State the type of mechanism that occurs in the formation of F and G. ...................................................................................................................................... (1) (c) Write equations, using curly arrows to represent the movement of electron pairs, to show the mechanism of the reaction in which either F or G is formed. Use Cl+ to represent the attacking species. (3) (d) Deduce the structures of compounds J, K and L. J K L (3) 43 (e) State the type of mechanism that occurs in the formation of J, K and L. ...................................................................................................................................... (1) (f) Write an equation to show the initiation step that occurs before either J, K or L can be formed, and state the condition needed. ...................................................................................................................................... ...................................................................................................................................... (2) (g) Write equations to show two propagation steps in the mechanism for the formation of compound K. ...................................................................................................................................... ...................................................................................................................................... ...................................................................................................................................... ...................................................................................................................................... (2) (h) Write an equation to show a termination step in which compound L is formed. ...................................................................................................................................... ...................................................................................................................................... (1) (i) Predict, giving a reason, whether methylbenzene or compound L undergoes nitration more readily. ...................................................................................................................................... ...................................................................................................................................... ...................................................................................................................................... ...................................................................................................................................... ...................................................................................................................................... (3) (Total 18 marks) 44 62. The compound 2-bromobutane, CH3CHBrCH2CH3 , can react with sodium hydroxide to form compounds M, N and O. Compound M, C4H10O, exists as a pair of optically active isomers. Compounds N and O, C4H8, are structural isomers, and compound O exists as a pair of geometrical isomers. (a) Draw diagrams to show the relationship between the two isomers of M. (2) (b) Draw diagrams to show the shapes of the two isomers of O. (2) (c) Write equations, using curly arrows to represent the movement of electron pairs, to show the mechanism of the reaction in which N is formed. (3) (Total 7 marks) 63. Which compound is a member of the same homologous series as 1-chloropropane? A. B. C. D. 1-chloropropene 1-chlorobutane 1-bromopropane 1,1-dichloropropane (1) 45 64. Which formula is a correct representation of pentane? A. B. C. D. CH3CH2CHCH2CH3 (CH3CH2)2CH3 CH3(CH2)3CH3 CH3(CH3)3CH3 (1) 65. What is the organic product of the reaction between ethanol and ethanoic acid? A. B. C. D. CH3CHO CH3COOCH3 CH3CH2COOCH3 CH3COOCH2CH3 (1) 66. Explain why the incomplete combustion of hydrocarbons is harmful to humans. ............................................................................................................................................... ............................................................................................................................................... ............................................................................................................................................... ............................................................................................................................................... (Total 2 marks) 67. Give the structural formulas for the isomers of molecular formula C 4H10 and state the name of each one. ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... (Total 4 marks) 68. Several compounds have the molecular formula C3H6O2. 46 Three of them, A, B and C, have the following properties: A is soluble in water and is acidic B and C are neutral and do not react with bromine. (a) Give a structural formula for each of these compounds and name them. ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... (6) (b) (i) Explain the solubility and acidity of A in water. ................................................................................................ ................................................................................................ ................................................................................................ ................................................................................................ ................................................................................................ ................................................................................................ (2) (ii) Write an equation for the reaction of A with sodium hydroxide solution. ................................................................................................ ................................................................................................ (1) (iii) Explain why B and C do not react with bromine. ................................................................................................ ................................................................................................ (1) 47 (c) State and explain which one of A, B or C has the highest boiling point. ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... (2) (d) (i) Name the class of compounds to which B and C belong and state a use of this class of compounds. ................................................................................................ ................................................................................................ (2) (ii) Name the two classes of compounds used to form B or C, and state the other product formed in this reaction. ................................................................................................ ................................................................................................ (3) (e) Suggest the structural formula of an isomer of C 3H6O2 which does react rapidly with bromine. Name this type of reaction, and describe an observation that can be made during the reaction. ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... ......................................................................................................... (3) (Total 20 marks) 48 69. (a) The reaction of warm aqueous KOH with 1-bromobutane occurs by an SN2 mechanism. Draw the mechanism for this reaction, including the structural formulas of 1-bromobutane, the transition state and the organic product. (4) (b) State and explain how the rate of the above reaction is affected when the concentration of the KOH is doubled. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... (2) (c) State and explain how the rate of reaction of 1-chlorobutane in the above SN2 reaction compares with that of 1-bromobutane. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... (2) (Total 8 marks) 70. Propan-1-ol has the following structural formula. H H C H H C H H C H O H 49 (a) Use Table 18 in the Data Booklet to identify two characteristic infrared absorption ranges for propan-1-ol and state the bonds responsible. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... (2) (b) Deduce the number of peaks and the ratio of the areas of the peaks in the 1HNMR spectrum of propan-1-ol. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... (2) (c) Propan-2-ol is an isomer of propan-1-ol. Draw the structure of propan-2-ol and explain why spectroscopy would be more useful than infrared spectroscopy in distinguishing 1HNMR between the two isomers. Explain your answer with reference to both techniques. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... (4) (Total 8 marks) 71. Consider the following steps in the reaction mechanism for the decomposition of nitryl chloride, NO2Cl, into nitrogen dioxide, NO2 and chlorine, Cl2. 1: 2: NO2Cl NO2 + Cl Cl + NO2Cl NO2 + Cl2 50 (a) Write the equation for the overall reaction. ..................................................................................................................................... (1) (b) Define the term activated complex. ..................................................................................................................................... ..................................................................................................................................... (1) (c) (i) Step 1 is the rate-determining step in the above reaction mechanism. State what is meant by the term rate-determining step. .......................................................................................................................... .......................................................................................................................... (1) (ii) Deduce the molecularity of the rate-determining step. .......................................................................................................................... .......................................................................................................................... (1) (Total 4 marks) 72. Propanal, CH3CH2CHO (Mr = 58), undergoes complete fragmentation in a mass spectrometer. What is the m/z value of the most intense line in its mass spectrum? A. B. C. D. 15 29 43 58 (1) 73. Which statement is correct about the reaction between methane and chlorine? A. B. C. D. It involves heterolytic fission and Cl- ions. It involves heterolytic fission and Cl radicals. It involves homolytic fission and Cl- ions. It involves homolytic fission and Cl radicals. (1) 51 74. Which formula is that of a secondary halogenoalkane? A. B. C. D. CH3CH2CH2CH2Br CH3CHBrCH2CH3 (CH3)2CHCH2Br (CH3)3CBr (1) 75. Which compound is converted to butanal by acidified potassium dichromate(VI) solution? A. B. C. D. butan-1-ol butan-2-ol butanone butanoic acid (1) 76. (a) Give the structural formulas of the four isomers of molecular formula C4H9Cl. State the name of each one and classify it as primary, secondary, or tertiary. ...................................................................................................................................... ...................................................................................................................................... ...................................................................................................................................... ...................................................................................................................................... ...................................................................................................................................... ...................................................................................................................................... ...................................................................................................................................... ...................................................................................................................................... ...................................................................................................................................... ...................................................................................................................................... ...................................................................................................................................... 52 ...................................................................................................................................... ...................................................................................................................................... ...................................................................................................................................... ...................................................................................................................................... ...................................................................................................................................... (8) (b) Each of the isomers reacts with aqueous sodium hydroxide. State what class of compound is produced by this reaction. ...................................................................................................................................... (1) (c) (i) Identify the type of isomer (primary, secondary or tertiary) which will react with aqueous sodium hydroxide almost exclusively by an S N1 mechanism. State the meaning of the symbols in the term SN1 mechanism. ............................................................................................................................ ............................................................................................................................ ............................................................................................................................ (2) (ii) Using the formula RCl to represent a chloroalkane, write an equation for the rate determining step of this reaction. ............................................................................................................................ ............................................................................................................................ (1) (Total 12 marks) 77. Some organic compounds can undergo dehydration. (a) State what is meant by the term dehydration and give an example of a dehydrating agent. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... (2) 53 (b) Two of the isomers of molecular formula C3H8O can be dehydrated to form a compound of molecular formula C3H6. Give the structural formulas and the names of these three compounds. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... (5) (c) (i) State the number of peaks and the ratio of their areas in the 1H NMR spectra of C3H6 and one of the isomers of C3H8O. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... (4) (ii) Use Table 18 in the Data Booklet to identify a strong absorption in the infrared spectrum of C3H8O which is not present in C3H6, and a strong absorption in C3H6 which is not present in C3H8O. In each case, state the absorption range and the bond responsible. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... (2) 54 (d) (i) The compound C3H6 can react with bromine. Write an equation for this reaction and name the product. State a visible change which accompanies the reaction. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... (3) (ii) Give the full structural formula of the product formed in part (d) (i), and identify, by using an asterisk (*), a chiral carbon atom. State what distinctive property a chiral carbon atom gives to a molecule. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... (2) (e) Name the type of polymerization reaction which C 3H6 undergoes and draw the structure of a section of the polymer chain formed from three monomer molecules. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... (2) (f) One of the isomers of formula C3H8O can be oxidized to form two different organic products, depending on the conditions used. Identify an appropriate oxidizing agent. Give structures for the two products and specify the conditions required for the formation of each. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... 55 ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... (5) (Total 25 marks) 78. Methylbenzene, C4H5CH3, reacts with Cl2 to form different products depending on the conditions used. For the gas-phase reaction of C6H5CH3 and Cl2 in ultraviolet light, (a) draw a structural formula for the product C7H7Cl . (1) (b) provide a stepwise mechanism, clearly labelling each step. (5) (c) explain the role of the ultraviolet light. ...................................................................................................................................... ...................................................................................................................................... (1) (Total 7 marks) 79. When hydrogen cyanide reacts with an aldehyde or a ketone the product molecule has one more 56 carbon atom. (a) Give a mechanism for the reaction of hydrogen cyanide with propanone. (4) (b) Write an equation for the acid hydrolysis of this product. State the two functional groups in the organic product. ...................................................................................................................................... ...................................................................................................................................... ...................................................................................................................................... ...................................................................................................................................... (2) (Total 6 marks) 57 ... View Full Document

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