Question 1

Which statement best describes a Bronsted-Lowry acid?

Accepted Answer

A substance that donates a proton.

Question 2

In the reaction $\mathrm{CH_3COOH} + \mathrm{H_2O} \rightleftharpoons \mathrm{CH_3COO^-} + \mathrm{H_3O^+}$, which species is the conjugate base?

Accepted Answer

$\mathrm{CH_3COO^-}$

Question 3

Which curved arrow in an acid-base reaction mechanism represents the base attacking the acid?

Accepted Answer

An arrow from the base's lone pair to the acid's hydrogen.

Question 4

Given the acid dissociation constant $K_a$ for an acid, which equation correctly relates $pK_a$ to $K_a$?

Accepted Answer

$pK_a = -\log K_a$

Question 5

Which of the following acids is the strongest, based on $pK_a$ values?

Accepted Answer

An acid with $pK_a = 7$

Question 6

If the $pK_a$ of the acid on the left is 16 and the $pK_a$ of the acid on the right is 43, which direction will the equilibrium favor?

Accepted Answer

Toward the right (products)

Question 7

Which factor is NOT part of the ARIO acronym for assessing conjugate base stability?

Accepted Answer

Solubility

Question 8

Why is acetic acid ($pK_a = 4.75$) more acidic than ethanol ($pK_a = 16$)?

Accepted Answer

The conjugate base of acetic acid is resonance stabilized.

Question 9

Which statement about induction is correct?

Accepted Answer

Induction stabilizes a negative charge by electron-withdrawing groups pulling electron density through sigma bonds.

Question 10

Which compound has the most acidic hydrogen: ethane ($pK_a = 50$), ethylene ($pK_a = 44$), or acetylene ($pK_a = 25$)?

Accepted Answer

Acetylene

Question 11

Why can't acids stronger than $\mathrm{H_3O^+}$ be used in water as a solvent?

Accepted Answer

Water will react with the strong acid, leveling its strength to that of $\mathrm{H_3O^+}$.

Question 12

Which of the following is a Lewis acid but NOT a Bronsted-Lowry acid?

Accepted Answer

$\mathrm{BF_3}$

Question 13

Which statement best explains why tert-butanol is less acidic than ethanol?

Accepted Answer

Tert-butoxide is less solvated due to steric hindrance, making its conjugate base less stable.

Question 14

Which of the following will most effectively stabilize a negative charge on a conjugate base?

Accepted Answer

A carbon atom in an sp orbital

Question 15

What is the effect of increasing the number of electron-withdrawing groups near a negative charge on a conjugate base?

Accepted Answer

It stabilizes the negative charge.

Question 16

Which of the following is true regarding the relationship between acid strength and conjugate base strength?

Accepted Answer

The stronger the acid, the weaker its conjugate base.

Question 17

Which of the following is NOT a correct use of curved arrows in acid-base mechanisms?

Accepted Answer

Indicating the movement of protons without electron movement.

Question 18

A reaction has $pK_a$ values of 50 for the acid and 15.7 for the conjugate acid. What is the ratio of products to reactants at equilibrium?

Accepted Answer

$10^{34}$

Question 19

Which of the following is a correct statement about counterions in acid-base reactions?

Accepted Answer

Counterions are necessary to balance the overall charge but are often omitted from reaction mechanisms.

Question 20

Which of the following is the most important factor for stabilizing a negative charge when comparing atoms in the same period?

Accepted Answer

Electronegativity

Acids and Bases: Principles, Quantification, and Mechanisms

Study Guide - Practice Questions