Question 1

Which of the following best describes the molecular geometry of the compound shown in the second image (a three-membered ring with three fused cyclopropane rings)?

Accepted Answer

Highly strained due to angle strain (bicyclo[1.1.0]butane)

Question 2

Given the reaction: $$\mathrm{CH_3CH_3} + \mathrm{Cl_2$} \rightarrow \mathrm{CH_3CH_2Cl} + \mathrm{HCl}$$, and the bond dissociation energies: $$\mathrm{C-H} (104 $$kcal/mol), $$\mathrm{Cl-Cl} (58 $$kcal/mol), $$\mathrm{C-Cl} (81 $$kcal/mol), $$\mathrm{H-Cl} (103 $$kcal/mol), calculate $$\Delta H^\circ$$ for the reaction.

Accepted Answer

$$\Delta H^\circ = -22$$ kcal/mol

Question 3

Which of the following is the correct IUPAC name for the molecule shown in image 7 (branched alkane)?

Accepted Answer

3-ethyl-6-isopropyl-2,2,7-trimethyldecane

Question 4

Which of the following cycloalkanes would have the highest boiling point?

Accepted Answer

Cyclodecane

Question 5

If the equilibrium constant $$K_{eq} of a $$reaction is 0.5, which of the following must be true?

Accepted Answer

Gibbs free energy ($$G) is $$positive.

Question 6

Which of the following is a carbocation?

Accepted Answer

$$\mathrm{CH_3CH_2^+}$$

Question 7

Which of the following reactive intermediates can best be described as both nucleophilic and electrophilic?

Accepted Answer

Carbenes

Question 8

Which of the following would NOT be a possible termination product in the photochemical chlorination of ethane?

Accepted Answer

$$\mathrm{CH_3CH_2Cl}$$

Question 9

Which of the following free radicals is the most stable?

Accepted Answer

Tert-butyl radical ($$\mathrm{(CH_3$)_3C\cdot})$$

Question 10

Which two reaction coordinate diagrams best illustrate the Hammond Postulate?

Accepted Answer

1 and 4

Question 11

Which of the following Newman projections represents the anti conformation for butane?

Accepted Answer

Projection 1

Question 12

Which of the following best describes the point marked with an asterisk (*) on the reaction coordinate diagram for free radical bromination of ethane?

Accepted Answer

Transition state

Question 13

Which of the following is the correct structure for cis-1,3-dimethylcyclohexane?

Accepted Answer

Both methyl groups on the same side of the ring (axial/equatorial)

Question 14

Which of the following best explains why cyclopropane is highly reactive compared to other cycloalkanes?

Accepted Answer

It has significant angle strain due to its bond angles.

Question 15

Which of the following statements about the Gibbs free energy equation $$\Delta G^\circ = -RT \ln K_{eq} is $$correct?

Accepted Answer

If $$K_{eq} \u003c 1$$, $$\Delta G^\circ is $$positive.

Question 16

Which of the following best describes the transition state in the free radical bromination of ethane?

Accepted Answer

It is a high-energy intermediate with partial bonds between ethane and bromine.

Question 17

Which of the following is NOT a possible resonance structure for the ethyl radical?

Accepted Answer

A structure with the radical on a hydrogen atom

Organic Chemistry Exam #2 – Step-by-Step Study Guidance

Study Guide - Practice Questions

Study Guide - Flashcards