(5 1. minutes, 12 points) Answer the following: a. Why is the bond angle smaller in NH3 (107.3) than it is in H2O (104.5)?
b. Why is H3O+ a stronger acid than +NH4 ?
c. Why is HBr a stronger acid than HCl?
d. What is the hybridization of the indicated atom?
O CH3 CCH3 CH3 C N
e. Give each of the atoms the appropriate formal change.
H
C H H
H
C H H
H
C H H
f. Which of the indicated bonds is longer?
H C H C
H or H H C C H
2. (5 minutes, 12 points) Answer the following: a. Which bond is more polar?
O H
or
N H
b. Which compound has the higher boiling point?
CH3 CH2 CH2 CH2 CH3
or
CH3 CHCH 2 CH3 CH3
c. Is the following compound an E or a Z isomer?
CH3 CH3 OCH 2 C CH3 CHCH 2 CH3 C CH2 CH2 CH2 Br CH2 CHCH 3
d. Which compound is the stronger acid?
CH3CHCH 2OH F
or
CH3CHCH 2OH Cl
e. Which compound is the stronger base?
CH3 CH2NH2
2
or
CH3 CH2 OH
f. Do the sp carbons and the indicted sp carbons lie in the same plane?
CH 3
3
3. (6 minutes, 22 points) Give a structure for each of the following: a. a secondary amine
b. a secondary alcohol
c. sec-butyl isobuty ether
d. vinyl chloride
e. allyl alcohol
f. 3-ethylcyclohexanol
g. N,N-dimethyl-2-butanamine
h. trans-2-heptene
i. the conjugate acid of ethanol
j. isohexyl bromide
k. 1,6-dimethylcyclohexene
4. (2 minutes, 8 points) Indicate whether each of the following statements is true or false: a. CH4 is a stronger acid than NH3. b. Ethyl methyl ether has a higher boiling point than 1-propanol. c. A pi bond is stronger than a sigma bond. d. Ethylmethylamine has a higher boiling point than pentylamine. T T T T F F F F
5. (5 minutes, 8 points) Answer the following: a. At what pH will ~ 10% of a compound with a pKa = 4.8 be in its basic form?
b. At what pH will 50% of a compound with a pKa = 4.8 be in its acidic form?
c. What kind of orbitals does berillium use to form the three identical bonds in BeH 2 ? (hint: Berillium has an atomic number = 4).
d. What is the molecular formula of a hydrocarbon with eight carbons that has 3 bonds and one ring?
6. (7 minutes, 12 points) Give the systematic name for each of the following compounds:
a. Br
CH3 b.
CH3 CH3
CH3 CHCH 2 CHCHCH 3
CH3 c. Br Br d. CH3 CHCH 2 CH2CCH2 CH2 CH3 CH3 Br CH2 CH3
CH3 e. CH3 CCH2 CH2 CH2 Cl OH
f.
CH3 CH2 CH2 CHCH2 CH2 CH2 CH2 CH3 CH2 CH2 CH2 CH3
7. (5 minutes, 6 points) Draw the following: a. the most stable of conformer cis-1-isopropyl-4-methylcyclohexane
b. 3 constitutional isomers with molecular formula C3H8O
c. a gauche conformer of hexane considering rotation about the C2-C3 bond
8. (3 minutes, 4 points) a. What products would be formed from the following acid-base reaction?
CH3OH
+
CH3NH3
+
b. Does the above reaction favor reactants or products?
9. (12 minutes, 18 points) Answer the following. a. The interaction between a solvent and a molecule or ion that is dissolved in that solvent is called solvation solulation alkylation dissolvation solubulation
b. Which of the following compounds is not a cis-disubstituted cyclohexane? 1,3-disubstituted: two equatorial substituents 1,2-disubstituted: one axial and one equatorial substituent 1,3-disubstituted: one axial and one equatorial substituent 1,3-disubstituted: two axial substituents 1,4-disubstituted: one axial and one equatorial substituent
c. Which of the following is the correct name for CH3CH2CH(NH-CH2CH3)-CH2CH2CH3? N-ethyl-3-hexanamine N-methyl-2-hexanamine N-methyl-3-hexanamine N-ethyl-2-hexanamine
d. What is the common name of N-methyl-1-propanamine? butylamine propylmethylamine methylpropylamine dimethylethylamine diethylamine
e. Which of the following statements is NOT true? Propyl alcohol is more soluble than butyl alcohol in water. A half-chair conformer is more stable than a boat conformer. A gauche conformer is less stable than an anti conformer. Dipoledipole interactions are stronger than van der Waals interactions. A chair conformer is more stable than a boat conformer. f. What atomic orbitals are used to form the C-O bond in an alcohol? a p orbital of C and a p orbital of O 3 an sp orbital of C and a p orbital of O an sp orbital of C and an sp orbital of O an sp orbital of C and an sp orbital of O an sp orbital of C and an sp orbital of O
3 2 3 3 3
g. Which of the following is not an appropriate name? isohexyl alcohol 3-methyl-2-pentanol 3-methyl-3-pentanol 2-methylcyclohexanol 1-methyl-2-cyclohexanol h. Select the molecule with the lowest concentration of the axially substituted conformer. isopropylcyclohexane propylcyclohexane tert-butylcyclohexane sec-butylcyclohexane ethylhexane
i. An axial methyl group in cyclohexane suffers from what disadvantage? one 1,2-diaxial interaction loneliness one 1,3-diaxial interaction two 1,3-diaxial interactions two 1,2-diaxial interactions