|
1 | | What is the IUPAC name of the following molecule? (12.0K) |
| | A) | 1,2-dimethylhexane |
| | B) | 2,4-dimethylcyclohexane |
| | C) | Dimethylcyclohexane |
| | D) | 1,3-dimethylcyclohexane |
|
|
2 | | Which compound has the highest melting point? |
| | A) | decane |
| | B) | 2,2,3,3-tetramethylbutane |
| | C) | 2,2,3-trimethylpentane |
| | D) | 4-methylnonane |
|
|
3 | | What is the correct IUPAC name of the following compound? (13.0K) |
| | A) | 3-propyl-4,5-dimethylhexane |
| | B) | 4-ethyl-5,6-dimethylheptane |
| | C) | 2,3-dimethyl-4-propylhexane |
| | D) | 4-ethyl-2,3-dimethylheptane |
|
|
4 | | Which of the following alkanes will have the lowest boiling point? |
| | A) | (9.0K) |
| | B) | (10.0K) |
| | C) | (10.0K) |
| | D) | (10.0K) |
|
|
5 | | What is the parent name for the following alkane?
(Note: The parent name corresponds to the longest continuous chain of carbon atoms.) (13.0K) |
| | A) | heptane |
| | B) | octane |
| | C) | nonane |
| | D) | decane |
|
|
6 | | For the following two pairs of molecules, identify which partner will have the higher boiling point.
(15.0K) |
| | A) | Pair 1: A; Pair 2: C |
| | B) | Pair 1: B; Pair 2: D |
| | C) | Pair 1: A; Pair 2: D |
| | D) | Pair 1: B; Pair 2: C |
|
|
7 | | How many isomers are there of C6H14? |
| | A) | four |
| | B) | five |
| | C) | six |
| | D) | seven |
|
|
8 | | How many isomers are there of C5H11Cl? |
| | A) | six |
| | B) | seven |
| | C) | eight |
| | D) | nine |
|
|
9 | | How many isomers are there of dimethylcyclopentane (neglecting enantiomers)? |
| | A) | 3 |
| | B) | 4 |
| | C) | 5 |
| | D) | 6 |
|
|
10 | | How many isomers are there of dimethylcyclopropane (neglecting enantiomers)? |
| | A) | 1 |
| | B) | 2 |
| | C) | 3 |
| | D) | 4 |
|
|
11 | | How many isomers are there of dimethylcyclohexane (neglecting enantiomers)? |
| | A) | 4 |
| | B) | 6 |
| | C) | 7 |
| | D) | 9 |
|
|
12 | | Which Newman projection does NOT represent the following compound? (16.0K) |
| | A) | (16.0K) |
| | B) | (17.0K) |
| | C) | (17.0K) |
| | D) | (17.0K) |
|
|
13 | | Which Newman projection has two gauche interactions? (16.0K) |
| | A) | (17.0K) |
| | B) | (17.0K) |
| | C) | (16.0K) |
| | D) | (16.0K) |
|
|
14 | | What are the total number of conformers (staggered and eclipsed) that you can draw for the following molecule? (15.0K) |
| | A) | 4 |
| | B) | 5 |
| | C) | 6 |
| | D) | 7 |
|
|
15 | | A “gauche” interaction costs 3.8 kJ/mol, a hydrogen–hydrogen eclipsing interaction costs 4.0 kJ/mol, a hydrogen–methyl eclipsing interaction costs 6.0 kJ/mol, and a methyl–methyl eclipsing interaction costs 11 kJ/mol.
What is the relative energy cost of the MOST stable conformer of 2,3-dimethylbutane? |
| | A) | 0 kJ/mol |
| | B) | 7.6 kJ/mol |
| | C) | 8.6 kJ/mol |
| | D) | 11.4 kJ/mol |
|
|
16 | | Which of the following statements about conformations is FALSE? |
| | A) | Conformers can be isolated and separated at room temperature. |
| | B) | Conformers are interconverted by rotation about sigma bonds. |
| | C) | For butane the staggered anti conformation is the most stable. |
| | D) | For ethane the eclipsed conformation is the least stable. |
|
|
17 | | Choose the correct Newman projection for 2-methylpentane. |
| | A) | (16.0K) |
| | B) | (17.0K) |
| | C) | (16.0K) |
| | D) | (16.0K) |
|
|
18 | | Which of the following is the MOST stable cycloalkane per CH2? |
| | A) | (9.0K) |
| | B) | (11.0K) |
| | C) | (11.0K) |
| | D) | (12.0K) |
|
|
19 | | Which of the following cycloalkanes has the MOST strain energy? |
| | A) | cyclobutane |
| | B) | cyclopentane |
| | C) | cyclohexane |
| | D) | cycloheptane |
|
|
20 | | A medium sized ring such as cyclooctane is less stable than cyclohexane. Which of the following statements describes cyclooctane? |
| | A) | It is planar and has an internal bond angle of 135°. |
| | B) | It is puckered and has a bond angle of 109°. |
| | C) | It has 16 pairs of eclipsed H–H steric interactions. |
| | D) | The heat of combustion per CH2 group is less than that for cyclohexane. |
|
|
21 | | Place the following structures properly on the (abbreviated) energy surface for cyclohexane ring reversal. (19.0K) (11.0K) |
| | A) | 1 = b or c, 2 = a, 3 = d, 4 = b or c |
| | B) | 1 = d, 2 = b or c, 3 = d, 4 = a |
| | C) | 1 = d, 2 = b or c, 3 = a |
| | D) | 1 = b or c, 2 = d 3 = a, 4 = b or c |
|
|
22 | | Which of the following cyclohexane conformations has the MOST energy (is the LEAST stable)? |
| | A) | chair |
| | B) | half-chair |
| | C) | boat |
| | D) | twist-boat |
|
|
23 | | The boat conformation has how many eclipsing H–H interactions? |
| | A) | 1 |
| | B) | 2 |
| | C) | 4 |
| | D) | 6 |
|
|
24 | | Which of the following statements regarding cyclohexanes is FALSE? |
| | A) | A cyclohexane ring never exists in a boat conformation. |
| | B) | A chair conformation of cyclohexane has no torsional strain. |
| | C) | A chair conformation of cyclohexane has no angle strain. |
| | D) | At equilibrium, 99% of the cyclohexane molecules are in a chair conformation. |
|
|
25 | | Which of the following molecules is trans-1, 2-dimethylcyclohexane? |
| | A) | (12.0K) |
| | B) | (13.0K) |
| | C) | (13.0K) |
| | D) | (13.0K) |
|
|
26 | | The equilibrium constant equals 1 for the interconversion of the two chair conformations of a dimethylcyclohexane when the methyl groups are in which positions? |
| | A) | both are equatorial |
| | B) | both are axial |
| | C) | one is axial and the other is equatorial |
| | D) | both are pseudo-equatorial |
|
|
27 | | How many gauche/diaxial interactions are present in cis-1,2-dimethylcyclohexane? |
| | A) | 1 gauche and 2 diaxial interactions |
| | B) | 2 gauche and 1 diaxial interactions |
| | C) | 1 gauche and 1 diaxial interactions |
| | D) | 2 gauche and 2 diaxial interactions |
|
|
28 | | Which of the following dimethylcyclohexane isomers have chair conformations that are mirror images? |
| | A) | cis-1,3 |
| | B) | trans-1,3 |
| | C) | cis-1,2 |
| | D) | trans-1,4 |
|
|
29 | | The balanced equation for the combustion of pentane is |
| | A) | 4 C5H12 + 2 O2 → 20 CH4 + 4 H2O |
| | B) | 2 C3H8 + O2 → 3 CH4 + 2 H2O |
| | C) | C5H12 + 8 O2 → 5 CO2 + 6 H2O |
| | D) | C3H8 + 5 O2 → 3 CO2 + 4 H2O |
|
|
30 | | Which of the following statements is NOT correct regarding the reactivity of alkanes? |
| | A) | Alkanes are generally inert. |
| | B) | Alkanes are often used as solvents for chemical reactions. |
| | C) | Alkanes react with acids and bases. |
| | D) | Alkanes react with halogens and oxygen upon ignition. |
|
|
31 | | Which of the following is NOT a source of strain in “boat” cyclohexane? |
| | A) | angle strain |
| | B) | torsional strain |
| | C) | “flagpole” or “bowsprit” interaction |
| | D) | eclipsing strain |
|