Question 1

Which of the following best describes a substitution reaction in organic chemistry?

Accepted Answer

A reaction where an atom or group of atoms other than hydrogen are exchanged between molecules.

Question 2

In the context of acid-base reactions, which of the following is the correct formula for the acid dissociation constant $$K_a$$?

Accepted Answer

$$K_a = \frac{[H^+][A^-]}{[HA]}$$

Question 3

Which of the following molecules would be expected to act as a nucleophile?

Accepted Answer

A molecule with a lone pair of electrons and a negative charge.

Question 4

Which of the following statements about the relationship between stability and reactivity in organic chemistry is correct?

Accepted Answer

Stability and reactivity generally have an inverse relationship.

Question 5

Given the following acid-base reaction, which direction will the equilibrium favor? $$CH_3COOH + OH^- \rightarrow CH_3COO^- + H_2O$$

Accepted Answer

The reaction will favor the products because $$OH^- is a $$stronger base than $$CH_3COO^-.$$

Question 6

Which of the following is NOT one of the four common indicators of reactivity in organic molecules?

Accepted Answer

Steric hindrance

Question 7

Which of the following acids has the lowest pKa value?

Accepted Answer

Acetic acid ($$CH_3COOH)$$

Question 8

Which of the following factors increases the inductive effect in a molecule?

Accepted Answer

Increasing the strength and number of electronegative atoms.

Question 9

Which of the following statements about resonance effects is correct?

Accepted Answer

Resonance effects stabilize the conjugate base, making the acid stronger.

Question 10

Which of the following hydrocarbons is the most acidic?

Accepted Answer

Ethyne ($$HC\equiv CH)$$

Question 11

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

Accepted Answer

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

Question 12

Which of the following best describes a nucleophile?

Accepted Answer

A species that donates an electron pair to form a new bond.

Question 13

Which of the following is a correct statement about the direction of electron movement in reaction mechanisms?

Accepted Answer

Arrows always move from regions of high electron density to low electron density.

Question 14

Which of the following is a strong acid according to the 'strong six' rule?

Accepted Answer

$$HClO_4$$

Question 15

Which of the following statements about $$pK_a is $$correct?

Accepted Answer

A lower $$pK_a$$ value indicates a stronger acid.

Question 16

Which of the following is the correct order of increasing $$pK_a$$ for the following functional groups: alcohol, alkane, carboxylic acid?

Accepted Answer

Carboxylic acid \u003c alcohol \u003c alkane

Question 17

Which of the following statements about homolytic and heterolytic bond cleavage is correct?

Accepted Answer

Homolytic cleavage results in the formation of radicals.

Question 18

Which of the following factors does NOT increase the stability of a conjugate base?

Accepted Answer

Steric hindrance around the negative charge.

Question 19

Which of the following is the correct definition of a Lewis acid?

Accepted Answer

A species that accepts an electron pair.

Question 20

Which of the following statements about hybridization and acidity is correct?

Accepted Answer

The more $$sp$$ character in the acid, the more acidic it is.

Fundamentals of Organic Chemistry: Reaction Types, Acidity, and Mechanisms

Study Guide - Practice Questions