Question 1

Which of the following statements correctly describes the Brønsted-Lowry definition of acids and bases?

Accepted Answer

An acid donates a proton; a base accepts a proton.

Question 2

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

Accepted Answer

$$\mathrm{CH_3COO^-}$$

Question 3

Which of the following best explains why curved arrows are used in acid-base reaction mechanisms?

Accepted Answer

They show the physical movement of electrons during bond making and breaking.

Question 4

Given the acid dissociation constant $$K_a$$, which statement is true for a strong acid?

Accepted Answer

$$K_a is $$much greater than 1.

Question 5

If the $$pK_a of $$sulfuric acid is $$-9$$ and the $$pK_a of $$hydrochloric acid is $$-7$$, how many times stronger is sulfuric acid compared to hydrochloric acid?

Accepted Answer

100 times stronger

Question 6

Which factor is most important for stabilizing a negative charge on an atom when comparing atoms in the same period?

Accepted Answer

Electronegativity

Question 7

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

Accepted Answer

Resonance stabilizes the negative charge by delocalizing it, making the acid stronger.

Question 8

Which of the following best describes the effect of induction on the stability of a conjugate base?

Accepted Answer

Electron withdrawing groups increase the stability of the conjugate base by dispersing negative charge.

Question 9

Consider the following carbanions: $$\mathrm{CH_3$^-} (sp$^3$$), $$\mathrm{CH_2$=CH^-} (sp$^2$$), and $$\mathrm{C\equiv CH^-} (sp). $$Which is the most stable?

Accepted Answer

$$\mathrm{C\equiv CH^-} (sp)$$

Question 10

Which of the following is the correct order of importance for the ARIO factors when assessing the stability of a conjugate base?

Accepted Answer

Atom \u003e Resonance \u003e Induction \u003e Orbital

Question 11

A reaction has reactants with $$pK_a = 15.7$$ and products with $$pK_a = 50. $$What is the ratio of products to reactants at equilibrium?

Accepted Answer

$$10^{34}$$

Question 12

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, converting it entirely to $$\mathrm{H_3O^+}.$$

Question 13

Which of the following is a correct statement about the leveling effect of water?

Accepted Answer

Water prevents the use of bases stronger than $$\mathrm{OH^-} as $$reagents.

Question 14

Why is tert-butanol less acidic than ethanol, even though both have oxygen as the atom carrying the negative charge?

Accepted Answer

tert-Butanol's conjugate base is less stabilized by solvation due to steric hindrance.

Question 15

Which of the following is true regarding counterions in acid-base reactions?

Accepted Answer

Counterions are necessary to balance the overall charge but do not participate in the reaction.

Question 16

Which statement best distinguishes the Lewis definition of acids and bases from the Brønsted-Lowry definition?

Accepted Answer

Lewis acids accept electron pairs, while Brønsted-Lowry acids donate protons.

Question 17

Which of the following reactions can be classified as a Lewis acid-base reaction but not a Brønsted-Lowry acid-base reaction?

Accepted Answer

Reaction of $$\mathrm{BF_3$}$$ with $$\mathrm{NH_3$} to $$form $$\mathrm{F_3B-NH_3$}$$

Question 18

A student wants to predict the position of equilibrium for an acid-base reaction but does not have $$pK_a$$ values. What is the best alternative approach?

Accepted Answer

Compare the stability of the conjugate bases using ARIO factors.

Question 19

Which of the following is a limitation of the ARIO method for predicting acidity?

Accepted Answer

ARIO sometimes fails, and $$pK_a$$ values are needed for exceptions.

Acids and Bases in Organic Chemistry: Concepts, Mechanisms, and Applications

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