Question 1

Which of the following best describes the geometry and hybridization of the central nitrogen atom in the nitrite ion ($$\mathrm{NO_2$^-}$$)?

Accepted Answer

Bent geometry, $$sp^2$$ hybridization

Question 2

Which of the following statements about the nitrite ion ($$\mathrm{NO_2$^-}) is $$FALSE?

Accepted Answer

The ion is overall nonpolar (zero net dipole)

Question 3

Which of the following molecules CANNOT contain a triple bond?

Accepted Answer

$$\mathrm{C_4H_7Br}$$

Question 4

Given the following pairs of molecules, which term best describes their relationship?

Molecule 1: $$\mathrm{CH_3CH_2CH_2CH_3}$$
Molecule 2: $$\mathrm{CH_3CH(CH_3$)CH_3$}$$

Accepted Answer

Constitutional isomers

Question 5

Which hydrogen in the following molecule is the most acidic?

$$\mathrm{CH_3COOH}$$

Accepted Answer

The hydrogen on the carboxyl group

Question 6

What is the approximate pKa of acetic acid ($$\mathrm{CH_3COOH}$$)?

Accepted Answer

$$5$$

Question 7

Which of the following best describes the relationship between cis-1,2-dimethylcyclohexane and trans-1,2-dimethylcyclohexane?

Accepted Answer

Stereoisomers

Question 8

Which of the following is TRUE about the lowest energy chair conformation of cis-1,2-dimethylcyclohexane?

Accepted Answer

One methyl group is axial and one is equatorial

Question 9

Which of the following acid-base reactions is most downhill (most favorable) in terms of potential energy?

Accepted Answer

Deprotonation of cyclopentadiene by hydroxide

Question 10

Which of the following best explains why the deprotonation of cyclopentadiene by hydroxide is so favorable?

Accepted Answer

The conjugate base is resonance stabilized

Question 11

How many important resonance structures exist for the nitrite ion ($$\mathrm{NO_2$^-}$$)?

Accepted Answer

2

Question 12

Which of the following molecules is most likely to have a bond angle closest to $$120^\circ$$?

Accepted Answer

$$\mathrm{NO_2$^-}$$

Question 13

Which of the following is NOT a possible resonance structure for the acetate ion ($$\mathrm{CH_3COO^-}$$)?

Accepted Answer

Both oxygens have a single bond to carbon and a negative charge

Question 14

Which of the following best describes the hybridization of the carbon atom in carbon dioxide ($$\mathrm{CO_2$}$$)?

Accepted Answer

$$sp$$

Question 15

Which of the following is a constitutional isomer of 2,3-dimethylpentane?

Accepted Answer

2,2,3-trimethylbutane

Question 16

Which of the following best describes the relationship between two molecules that have the same molecular formula but different connectivity?

Accepted Answer

Constitutional isomers

Question 17

Which of the following is TRUE about the bond polarization in the nitrite ion ($$\mathrm{NO_2$^-}$$)?

Accepted Answer

Bond polarization arrows point toward the oxygen atoms

Question 18

Which of the following molecules has the highest number of possible constitutional isomers?

Accepted Answer

$$\mathrm{C_5H_{12}}$$

Question 19

Which of the following is the correct IUPAC name for the molecule with the structure $$\mathrm{CH_3CH=CHCH_2CH_3}$$?

Accepted Answer

2-pentene

Organic Chemistry Midterm Study Guidance – Resonance, Hybridization, Acidity, Isomerism, and Conformations

Study Guide - Practice Questions