second_exam - Ms University ‘ ~_L—_rxDé“...

Info iconThis preview shows pages 1–8. Sign up to view the full content.

View Full Document Right Arrow Icon
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 2
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 4
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 6
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 8
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Ms University ‘ ' ~_L—_rxDé“ Wmfint9fthfinist. CHE 1129 -15se‘c'ond’ Eiaiiiiiiation, Dr. David Brown . Dr. Joseph Sarra Dr. Steven Graham ' I Dr. Adejare Adeniran NAME LD. # INSTRUCTIONS 1. Write your name and the Last Four digits of your ID No. on this page, and on the answer (Scantron) sheet. 2. Circle the name of your instructor above. 3. Use the examination pages to work out your answers. 4. ‘ For each of the 25 questions, indicate the Correct answer on the scantron with a #2 pencil. ‘ Each question is Worth four points. A non-programmable, non—graphic calculator may be used. Answers will be posted on the notice board opposite to Room 324, St. Albert Hall. 5. Hand in the examination questions, any scrap page, and the scantron sheet. 6. You will have up to 90 Minutes to complete the exam. PROPER CONDUCT DURING EXAMINATIONS: 1. Communication between students by any means is prohibited. 2. Possession of any unauthorized papers is prohibited. 3. a No paging devices or cell phones allowed. 4. Allflbooks, papers, and jackets should be placed in the front of the room. 5. Violation of any of the above rules will result in a minimum penalty of a grade of zero for this exam. A PERIODIC TABLE AND A DATA SHEET ARE ATTACHED FOR YOUR CONVENIENCE no: to at m an this material may be protected by =opyright law (Title’ 1.7 (End } ‘ “ WMNMIr . l. 2.. 3. 4. Which of the following is the weakest acid? A. HNOz pKa = 3.15 B. HF pKa = 3.17 @ HOCl pKa = 7.52 D. HI03 _ pKa = 0.23 Which of the following acids would have the weakest conjugate base? A. HC2H302 pKa = 4.74 B. ,HOCN pKa = 3.46 (CD HCzH202Cl pKa = 2.87 .D. HOCl pKa = 7.52 A 0.010 M morphine solution has a pH 'of 10.00. What percentage of the morphine molecules have ionized? (Morphine is a weak base.) 2 A. 10% . B. 25% @ 1.0% C. 5.0 % Nicotinic acid has a Ka value of 1.4 x 10'5. VWhat is the pH of a 0.050 M solution of this acid? (19 3.08 7.85 A. 6.15 C. 10.9 D. 5. 6. 7. Which of the following salts contain an acidic cation? @ CH3NH3CI V i B. C. KOCl D. NaCl CsBr In predicting the acid-base properties of salt Solutions, which of the follOwing statements is true? A. If a salt has a cation that is acidic and an anion that isbasic, the pH of the solution will be determined by the acidic cation only. C. D. If neither the cation nor the anion can affect the pH, the solution will be neutral. If the cation is non-acidic, and the anion basic, the solution will have a pH less than 7.0. Ifthe cation is acidic and the anion extremely weak as base, the solution will have a pH greater than 7 .0. 1 Which of the following compounds will dissolve in water to form basic solutions? I KHC03 11 Al(N03)3 , 111 NaOCl A. I only ' B. II only @ IandDIonly D. I,]Iand]]I What is the pH of a 0.10M solution of NH4C1? [Kb = 1.8 x 10'5 for NH3 ] A. 8.87 B. 11.4 C. 7.00 @ 5.13 9. Which of the following is true of Buffers? All buffers fiJnction by shifting the equilibrium between a conjugate acid-base pair. B. All buffers must have pH Values equal to 7.00 C. There is absolutely no change in the pH of a buffer when a small amount of strong acid or strong base is added. D. ' The pH of a buffer decreases when it is diluted. 10. Information regarding equal volumes of two buffer systems X and Y are given below. X I IS 0.11 M in NaC2H302 and also 0.09 M in HC2H302_ Y I IS 0.44 M in NaC2H302 and also 0.36 M in HC2H302_ Which of the following is false? > A. System Y has the greater buffer capacity The pH of system X is lower than that of Y. The buffering ability of Y is greater than that of X. C. D. Both systems have the same pH value. 11. What mole ratio of NH3 to NH4+ would give a buffer with a pH of 9.25? A. 10 B. 5.6 x10” @ 1.0 D. 1.8 x10'5 12. For thereaction outlined below, AH" = -217.1kJ. CaO (s) + 211C] (g) —> CaClz(s)' + H20(g).‘ What is the value Of AE" ? A. -216.9kJ -214.6kJ C. -219.9kJ D. —217.3 k] 13. Which of the following series correctly places the cycloalkanes in order of decreasing ring strain? [ A > B means A has more strain than B ] A. Cyclopentane » > Cyclobutane > Cyclohexane B. Cyclopropane ‘ > V Cyclohexane > Cyclopentane C. Cyclohexane > Cyclopentane > Cyclobutane @ Cyclopropane > Cyclobutane > Cyclohexane 14. What is the IUPAC name for the following compound? 4-tert-Butyl-2-methylheptane . “F‘s B. 2,5,5,5-Tetramethy1heptane CHscHCH2?HCHZCHZCH3 C. l-Isobutylel-tert-butylbutane C(CH3)3 D. 3-Isobutyl-2,2-dimethylhexane 15. How many different compounds (“constitutional” or “structur ” isomers) are possible for an alkane with a molecular formula of Can? . A. 1 - B. 2 @3 D4 16. Which of the following is correct regarding alkanes? A. All carbons are sp3 hybridized B Free rotation about sigma bonds is possible C. Staggered conformations are of lower energy than are eclipsed conformations D All of the above 17. How many tertiary (3°) hydrogens are in the structure of 2-Methylbutane? @1 B.2 c, 0’ l I D. 9 18. Which of the following statements concerning thermodynamics is true? H . The standard entropy, S", for an element in its standard state is zero. 11. The enthalpy change, AB”, is the heat of reaction at constant pressure. III. The free "energy change, AG”, depends on both A110 and AS0 , and must be ' ' negative for a reaction to be spontaneous. A. I only B. 11 only C. Blonly D. II and Ill 19. Which of the following has the largest entropy? @ H20 (g) B. H20 (1) C. NaCl (s) D. They all have the same entropy 20, Which one of the following reactions should have a pasitive value for AS? ' A. Ba(OH)2 (s) + €02 (g) ,—> BaCO3 (s); + H20 (1) N202 (g) , —+ 2N0 (g) N2 (g) + 3 H2 (g) -> 2 NH3 (g) was AgNO3 (aq) + HCl (aq) -—> AgCl (s) + HNO3 (aq) 21. Referring to the structure below, l—EthyleZ-methyl cyclohexane, which of the following would be the ‘most'stable? CHZCH3 : CH3 The cisfconforrnation where Methyl is equatorial and Ethyl is axial A. The trans-conformation where both groups are equatorial C. The cis-conformation where Methyl is axial and Ethyl is equatorial D. The trans-conformation where both groups are axial. 22. Given that AH° = — 92.2 k] and AG° = — 33.4 k], calculate the AS° for the following reaction I i (assume 25 °C): ' ~ N2(g)+3flz(g)=2NH3(g) A. —-125.6kJ @ -197.3J/K C. — 58.8 k] ’ D. — 2.35 J/K 23. 24. Which of the following processes is not spontaneous? I A pile ofbr’icks becoming a brick wall B. Ice freezing at —25 °C C. A boulder rolling down a hill D. Dissolving sodium chloride in water Which of the following statements is false regarding cyclohexane? V A. In one of the conformations, there are only two flagpole hydrogens B. The ‘fboat” form is higher in energy than the"“chair” form. C. the chlorination of ethane? CH3€H2' +1 or —>" CH3CH2C1 A B. CH3CH2' + CH3CH§§ —>‘ CH3CH2CH2CH3 c or + (:12‘ Cl' -) @ CH3CH2‘ + 012 —> CH3CH2C1 + Cl- ...
View Full Document

This note was uploaded on 04/06/2008 for the course CHEM 10765 taught by Professor Brown during the Spring '08 term at St. Johns Duplicate.

Page1 / 8

second_exam - Ms University ‘ ~_L—_rxDé“...

This preview shows document pages 1 - 8. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online