reaction involving the transfer of a proton from an acid to water, yielding hydronium ions and the conjugate base of the acid

species that may either donate or accept a proton in a Brønsted-Lowry acid-base reaction

species that can act as either an acid or a base

reaction between identical species yielding ionic products; for water, this reaction involves transfer of protons to yield hydronium and hydroxide ions

reaction involving the transfer of a proton from water to a base, yielding hydroxide ions and the conjugate acid of the base

substance formed when a base gains a proton

substance formed when an acid loses a proton

ion-product constant for water (K_w)

equilibrium constant for the autoionization of water

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Chemistry 2e · 14.1 Brønsted-Lowry Acids and Bases

Brønsted-Lowry Acids and Bases: practice problems

7 problems from the book, with its answers. Check your working, or have any of them explained to you on the whiteboard.

Exercises 1
Write equations that show NH₃ as both a conjugate acid and a conjugate base.
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Exercises 3
Show by suitable net ionic equations that each of the following species can act as a Brønsted-Lowry acid:
(a) $H_{3} O^{+}$
(b) HCl
(c) NH₃
(d) CH₃CO₂H
(e) $NH_{4}^{+}$
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Exercises 5
Show by suitable net ionic equations that each of the following species can act as a Brønsted-Lowry base:
(a) H₂O
(b) OH⁻
(c) NH₃
(d) CN⁻
(e) S²⁻
(f) $H_{2} PO_{4}^{-}$
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Exercises 7
What is the conjugate acid of each of the following? What is the conjugate base of each?
(a) OH⁻
(b) H₂O
(c) $HCO_{3}^{-}$
(d) NH₃
(e) $HSO_{4}^{-}$
(f) H₂O₂
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Exercises 9
Identify and label the Brønsted-Lowry acid, its conjugate base, the Brønsted-Lowry base, and its conjugate acid in each of the following equations:
(a) $HNO_{3} + H_{2} O ⟶ H_{3} O^{+} + NO_{3}^{-}$
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Exercises 11
What are amphiprotic species? Illustrate with suitable equations.
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Exercises 13
State which of the following species are amphiprotic and write chemical equations illustrating the amphiprotic character of these species.
(a) $NH_{3}$
(b) $HPO_{4}^{2-}$
(c) Br⁻
(d) $NH_{4}^{+}$
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Key terms · 10

acid ionization: reaction involving the transfer of a proton from an acid to water, yielding hydronium ions and the conjugate base of the acid
amphiprotic: species that may either donate or accept a proton in a Brønsted-Lowry acid-base reaction
amphoteric: species that can act as either an acid or a base
autoionization: reaction between identical species yielding ionic products; for water, this reaction involves transfer of protons to yield hydronium and hydroxide ions
base ionization: reaction involving the transfer of a proton from water to a base, yielding hydroxide ions and the conjugate acid of the base
Brønsted-Lowry acid: proton donor
Brønsted-Lowry base: proton acceptor
conjugate acid: substance formed when a base gains a proton
conjugate base: substance formed when an acid loses a proton
ion-product constant for water (K_w): equilibrium constant for the autoionization of water

Learn 14.1 on the whiteboard

The tutor teaches the whole section, drawing it out step by step and answering your questions as you go.

Read 14.1 in the textbook · This section on openstax.org

Brønsted-Lowry Acids and Bases: practice problems

7 problems from the book, with its answers. Check your working, or have any of them explained to you on the whiteboard.

Exercises 1

Write equations that show NH₃ as both a conjugate acid and a conjugate base.

Exercises 3

Show by suitable net ionic equations that each of the following species can act as a Brønsted-Lowry acid:

(a) $H_{3} O^{+}$

(b) HCl

(d) CH₃CO₂H

(e) $NH_{4}^{+}$

Exercises 5

Show by suitable net ionic equations that each of the following species can act as a Brønsted-Lowry base:

(a) H₂O

(b) OH⁻

(d) CN⁻

(e) S²⁻

(f) $H_{2} PO_{4}^{-}$

Exercises 7

What is the conjugate acid of each of the following? What is the conjugate base of each?

(a) OH⁻

(b) H₂O

(d) NH₃

(e) $HSO_{4}^{-}$

(f) H₂O₂

Exercises 9

Identify and label the Brønsted-Lowry acid, its conjugate base, the Brønsted-Lowry base, and its conjugate acid in each of the following equations:

(a) $HNO_{3} + H_{2} O ⟶ H_{3} O^{+} + NO_{3}^{-}$

Exercises 11

What are amphiprotic species? Illustrate with suitable equations.

Exercises 13

State which of the following species are amphiprotic and write chemical equations illustrating the amphiprotic character of these species.

(a) $NH_{3}$

(b) $HPO_{4}^{2-}$

(d) $NH_{4}^{+}$

Key terms · 10

acid ionization: reaction involving the transfer of a proton from an acid to water, yielding hydronium ions and the conjugate base of the acid
amphiprotic: species that may either donate or accept a proton in a Brønsted-Lowry acid-base reaction
amphoteric: species that can act as either an acid or a base
autoionization: reaction between identical species yielding ionic products; for water, this reaction involves transfer of protons to yield hydronium and hydroxide ions
base ionization: reaction involving the transfer of a proton from water to a base, yielding hydroxide ions and the conjugate acid of the base
Brønsted-Lowry acid: proton donor
Brønsted-Lowry base: proton acceptor
conjugate acid: substance formed when a base gains a proton
conjugate base: substance formed when an acid loses a proton
ion-product constant for water (K_w): equilibrium constant for the autoionization of water

Learn 14.1 on the whiteboard

The tutor teaches the whole section, drawing it out step by step and answering your questions as you go.

Read 14.1 in the textbook · This section on openstax.org