Question 1

Which of the following best describes an Arrhenius acid?

Accepted Answer

A substance that produces hydronium ions ($$H_3O^+) $$when dissolved in water.

Question 2

According to the Brønsted-Lowry definition, which of the following is a base?

Accepted Answer

A substance that accepts a proton ($$H^+).$$

Question 3

Which of the following is an example of a polyprotic acid?

Accepted Answer

H_2SO_4

Question 4

Why is the second dissociation step of a polyprotic acid generally harder than the first?

Accepted Answer

The anion formed after the first dissociation is already negatively charged, making it harder to remove another positively charged proton due to electrostatic attraction.

Question 5

Which of the following statements about strong acids is correct?

Accepted Answer

Strong acids have weak conjugate bases.

Question 6

Given the equilibrium $$HA + H_2O \rightleftharpoons H_3O^+ + A^-$$, which species is the conjugate base?

Accepted Answer

$$A^-$$

Question 7

Which of the following best describes an amphoteric substance?

Accepted Answer

A substance that can act as either an acid or a base depending on the reaction.

Question 8

What is the value of the ion-product constant for water ($$K_w) at 25$$°C?

Accepted Answer

$$1.0 	imes 10$$^{-14}$$

Question 9

A solution has $$[H_3O^+] = 1 	imes 10$$^{-8}$$ M and $$[OH^-] = 1 	imes $$10^{-6} M. $$How would you classify this solution?

Accepted Answer

Basic

Question 10

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

Accepted Answer

A stronger acid has a weaker conjugate base.

Question 11

Which equation correctly represents the acid dissociation constant ($$K_a) $$for the reaction $$HA + H_2O \rightleftharpoons H_3O^+ + A^-$$?

Accepted Answer

$$K_a = \frac{[H_3O^+][A^-]}{[HA]}$$

Question 12

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

Accepted Answer

Equilibrium always favors the formation of the weaker acid and weaker base.

Question 13

Which of the following is a characteristic of a strong base?

Accepted Answer

It grabs and holds a proton tightly.

Question 14

Which of the following best explains why ammonia ($$NH_3) is $$considered a Brønsted-Lowry base?

Accepted Answer

It accepts a proton from water using its lone pair of electrons.

Question 15

Which of the following is true for a weak acid?

Accepted Answer

Its equilibrium favors the undissociated form.

Question 16

If a solution has $$[H_3O^+] \u003e 1 	imes 10$$^{-7}$$ M, how is it classified?

Accepted Answer

Acidic

Question 17

Which of the following is a real-life example of an amphoteric substance?

Accepted Answer

Water ($$H_2O)$$

Question 18

Which of the following best describes the behavior of a strong acid in water?

Accepted Answer

It is completely ionized, producing $$H_3O^+$$ ions.

Question 19

Which of the following is the correct expression for the autoionization of water?

Accepted Answer

$$2H_2O \rightleftharpoons H_3O^+ + OH^-$$

Acids and Bases: Definitions, Strength, Dissociation, and Amphoteric Water

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