Question 1

Which of the following best describes constitutional isomers?

Accepted Answer

Molecules with the same molecular formula but different connectivity of atoms.

Question 2

Given the following pair of compounds, which is more acidic?

Compound A: $$CH_3COOH$$ 
Compound B: $$CH_3CH_2OH$$

Accepted Answer

Compound A ($$CH_3COOH)$$

Question 3

Which of the following is the correct electron configuration for a carbon atom in its ground state?

Accepted Answer

$$1s^2$$ $$2s^2$$ $$2p^2$$

Question 4

Which of the following best explains why $$CH_3CH_2OH$$ has a higher boiling point than $$CH_3OCH_3$$?

Accepted Answer

Because $$CH_3CH_2OH$$ can form hydrogen bonds.

Question 5

Which of the following is a correct application of Hund's rule?

Accepted Answer

Electrons occupy degenerate orbitals singly before pairing.

Question 6

Which of the following molecules is a constitutional isomer of $$C_4H_{10}$$?

Accepted Answer

$$CH_3CH(CH_3$)CH_3$

Question 7

Which of the following statements about the Pauli exclusion principle is correct?

Accepted Answer

No two electrons in an atom can have the same set of four quantum numbers.

Question 8

Which of the following best describes the mechanism of nucleophilic substitution ($$S_N2) $$reactions?

Accepted Answer

A concerted one-step mechanism where the nucleophile attacks as the leaving group departs.

Question 9

Which of the following pairs of conformational representations of ethane has lower energy?

Accepted Answer

Staggered conformation

Question 10

Which of the following is the correct Lewis structure for $$CO_2$$?

Accepted Answer

O=C=O, with each O atom having two lone pairs

Question 11

Which of the following is the correct order of increasing acidity for the following compounds: $$CH_4$$, $$NH_3$$, $$H_2O$$, $$HF$$?

Accepted Answer

$$CH_4$$ \u003c $$NH_3$$ \u003c H_2O \u003c HF$$

Question 12

Which of the following best describes the difference between a constitutional isomer and a stereoisomer?

Accepted Answer

Constitutional isomers have different connectivity; stereoisomers have the same connectivity but different spatial arrangement.

Question 13

Which of the following is the correct electron configuration for the $$O^{2-}$$ ion?

Accepted Answer

$$1s^2$$ $$2s^2$$ $$2p^6$$

Question 14

Which of the following is a correct statement about the stability of cyclohexane conformations?

Accepted Answer

The chair conformation is more stable than the boat conformation.

Question 15

Which of the following is the correct molecular formula for isobutane?

Accepted Answer

$$C_4H_{10}$$

Question 16

Which of the following best explains why $$H_2O is $$more acidic than $$NH_3$$?

Accepted Answer

Oxygen is more electronegative than nitrogen, stabilizing the negative charge on the conjugate base.

Question 17

Which of the following is the correct number of valence electrons for a nitrogen atom?

Accepted Answer

5

Question 18

Which of the following is the correct structure for tert-butyl cation?

Accepted Answer

$$(CH_3$)_3C^+$$

Question 19

Which of the following is the correct order of increasing energy for the atomic orbitals?

Accepted Answer

$$1s \u003c 2s \u003c 2p$$

Question 20

Which of the following is a correct statement about the relationship between resonance and acidity?

Accepted Answer

Resonance stabilization of the conjugate base increases acidity.

Organic Chemistry Midterm Exam Structure and Study Guide

Study Guide - Practice Questions