Deck 15: Acids and Bases

Question 1

What is the conjugate acid of HCO₃⁻ ?

A) H₃O⁺
B) H₂O
C) CO₃^2-
D) OH⁻
E) H₂CO₃

Answer 1

H₂CO₃

Question 2

Which of the following is a general property of a base?

A) Bases have sour taste.
B) Bases turn blue litmus paper red.
C) Bases leave red litmus paper unchanged.
D) Bases turn red litmus paper blue.
E) Bases easily dissolve many metallic elements.

Answer 2

Bases turn red litmus paper blue.

Question 3

Identify the triprotic acid.

A) HNO₃
B) H₃PO₄
C) H₂SO₃
D) HClO₄
E) H₂SO₄

Answer 3

H₃PO₄

Question 4

Which of the following is an Arrhenius base?

A) CH₃CO₂H
B) NaOH
C) CH₃OH
D) LiCl
E) H₂CO₃

Question 5

What is the conjugate base of H₂PO₄⁻ ?

A) HPO₄^2-
B) PO₄^3-
C) H₃PO₄
D) H₃O⁺
E) OH⁻

Question 6

Which of the following is an Arrhenius acid?

A) H₂SO₄
B) LiOH
C) NH₂CH₃
D) CH₃CH₃
E) NH₃

Question 7

Which of the following is the acid found in our stomachs?

A) H₂SO₄
B) HI
C) HCl
D) HF
E) HBr

Question 8

Identify acid, base, conjugate acid, and conjugate base in the following reaction: H₂CO₃(aq) + H₂O(l) ⇌ HCO₃^-(aq) + H₃O⁺(aq)

A) H₂CO₃ is an acid, H₂O is a base, HCO₃^- is a conjugate base, and H₃O⁺ is a conjugate acid.
B) H₂CO₃ is a conjugate acid, H₂O is a conjugate base, HCO₃^- is a base, and H₃O⁺ is an acid.
C) H₂CO₃ is an acid, H₂O is a conjugate base, HCO₃^- is a base, and H₃O⁺ is a conjugate acid.
D) H₂CO₃ is a conjugate acid, H₂O is a base, HCO₃^- is a conjugate base, and H₃O⁺ is an acid.
E) H₂CO₃ is an acid, H₂O is a conjugate acid, HCO₃^- is a base, and H₃O⁺ is a conjugate base.

Question 9

Which of the following is a general property of an acid?

A) Acids have sour taste.
B) Acids are not able to dissolve metals.
C) Acids turn red litmus paper blue.
D) Acids leave blue litmus paper unchanged.
E) All acids are dense liquids.

Question 10

Identify the monoprotic acid.

A) H₂CO₃
B) NH₃
C) H₃PO₄
D) H₂SO₄
E) HBr

Question 11

Which of the following is the correct Arrhenius definition of acids?

A) An acid is a substance that produces H⁺ ions in aqueous solutions.
B) An acid is a substance that reacts with H⁺ ions in aqueous solutions.
C) An acid is a substance that produces OH^- ions in aqueous solutions.
D) An acid is a substance that decreases the amount of H⁺ ions in aqueous solutions.
E) An acid is a substance that does not alter the amount of H⁺ ions in aqueous solutions.

Question 12

Identify the weak diprotic acid.

A) HNO₃
B) H₃PO₄
C) H₂SO₃
D) HClO₄
E) H₂SO₄

Question 13

Which of the following is a Bronsted-Lowry base?

A) CH₄
B) HCN
C) NH₃
D) Cl₂
E) B₂H₆

Question 14

Identify the diprotic acid.

A) HNO₃
B) HCl
C) CH₃COOH
D) H₂SO₄
E) HClO₄

Question 15

Which of the following species is amphoteric?

A) CO₃^2-
B) HCl
C) NH₄⁺
D) HPO₄^2-
E) NaOH

Question 16

Which of the following groups is found in carboxylic acids (like acetic acid)?

A)
B)
C)
D)
E)

Question 17

Which of the following is a conjugate acid-base pair?

A) NH₄⁺/NH₃
B) H₃O⁺/OH⁻
C) H₂SO₃/SO₃²⁻
D) SO₄^2-/SO₃^2-
E) NaOH/Na⁺

Question 18

Which of the following is correct?

A) According to the Bronsted-Lowry theory, an acid is a proton donor while a base is a proton acceptor.
B) According to the Bronsted-Lowry theory, an acid is a proton acceptor while a base is a proton donor.
C) According to the Bronsted-Lowry theory, an acid is a proton donor while a base is a hydroxide ion acceptor.
D) According to the Bronsted-Lowry theory, an acid is a hydroxide donor while a base is a proton acceptor.
E) According to the Bronsted-Lowry theory, an acid is a hydroxide donor while a base is a hydroxide acceptor.

Question 19

Which of the following is the correct Arrhenius definition of bases?

A) A base is a substance that produces H⁺ ions in aqueous solutions.
B) A base is a substance that reacts with OH^- ions in aqueous solutions.
C) A base is a substance that decreases the amount of OH^- ions in aqueous solutions.
D) A base is a substance that produces OH^- ions in aqueous solutions.
E) A base is a substance that does not change the concentration of OH^- ions in aqueous solutions.

Question 20

Which of the following is a Bronsted-Lowry acid?

A) NH₄⁺
B) CH₄
C) NH₂^-
D) NH₃
E) Br₂

Question 21

Find the correct equilibrium constant that shows the ionization constant of a weak acid HA.

A) K_a =
B) K_a =
C) K_a =
D) K_a =
E) K_a =

Question 22

Which of the following is TRUE?

A) A neutral solution contains [H₂O] = [H₃O⁺]
B) A neutral solution does not contain any H₃O⁺ or OH^-
C) An acidic solution has [H₃O⁺] > [OH⁻]
D) A basic solution does not contain H₃O⁺
E) An acidic solution does not contain OH^-

Question 23

On which equilibrium does the strength of an acid HA depend on?

A) HA(aq) + H₂O(l) ⇌ H₂A⁺(aq) + OH^-(aq)
B) HA(aq) + H₂O(l) ⇌ A^-(aq) + H₃O⁺(aq)
C) HA(aq) + H₂O(l) ⇌ H(HO)A^-(aq) + H⁺(aq)
D) HA(aq) + OH^-(aq) ⇌ A^-(aq) + H₂O(l)
E) HA(aq) + HA(aq) ⇌ H₂A⁺(aq) + A^-(aq)

Question 24

Which of the following is a strong acid?

A) C₆H₅CO₂H
B) HCN
C) HClO₄
D) NH₄⁺
E) H₂O

Question 25

What is the K_w of pure water at 50.0 °C, if the pH is 6.630?

A) 2.34 × 10^-7
B) 5.50 × 10^-14
C) 2.13 × 10^-14
D) 1.00 × 10^-14
E) 2.34 × 10^-14

Question 26

Calculate the pH of a solution that contains 3.9 × 10^-4 mol L^-1 H₃O⁺ at 25 °C.

A) 4.59
B) 3.41
C) 10.59
D) 9.41
E) 0.59

Question 27

What is the concentration of hydroxide ions in pure water at 30.0 °C if K_w at this temperature is 1.47 × 10^-14?

A) 1.00 × 10^-7 mol L^-1
B) 1.30 × 10^-7 mol L^-1
C) 1.47 × 10^-7 mol L^-1
D) 8.93 × 10^-8 mol L^-1
E) 1.21 × 10^-7 mol L^-1

Question 28

The stronger the acid, ________.

A) the stronger the conjugate acid
B) the stronger the conjugate base
C) the weaker the conjugate base
D) the weaker the conjugate acid
E) the stronger the conjugate acid-base pair

Question 29

Calculate the pOH of a solution that contains 3.9 × 10^-4 mol L^-1 H₃O⁺ at 25 °C.

A) 4.59
B) 3.31
C) 10.59
D) 9.14
E) 0.59

Question 30

Which of the following correctly describes the characteristics of a strong acid?

A) ionizes only partially in aqueous solutions
B) has a very electron positive atom attached to the oxygen
C) has a nonpolar bond
D) is completely ionized in aqueous solution
E) is always monoprotic

Question 31

Which of the following statements is TRUE?

A) A strong acid is composed of a proton and an anion that have a very strong attraction for one another.
B) A weak base is composed of a cation and an anion with a very weak attraction between them.
C) A strong acid has a strong conjugate base.
D) The conjugate base of a very weak acid is stronger than the conjugate base of a strong acid.
E) The dissociation reaction of a weak acid is completely shifted to the right.

Question 32

Which of the following solutions would have the highest pH? Assume that they are all 0.10 mol L^-1 in acid at 25 °C? The acid is followed by its K_a value.

A) HF, 3.5 × 10^-4
B) HCN, 4.9 × 10^-10
C) HNO₂, 4.6 × 10^-4
D) HCHO₂, 1.8 × 10^-4
E) HClO₂, 1.1 × 10^-2

Question 33

Which of the following acids will have the strongest conjugate base?

A) HCl
B) HClO₄
C) HNO₃
D) HCN
E) HI

Question 34

Calculate the concentration of OH⁻ in a solution that contains 3.9 × 10^-4 mol L^-1 H₃O⁺ at 25 °C. Also identify the solution as acidic, basic, or neutral.

A) 2.6 × 10^-11 mol L^-1, acidic
B) 2.6 × 10^-11 mol L^-1, basic
C) 3.9 × 10^-4 mol L^-1, neutral
D) 2.7 × 10^-2 mol L^-1, basic
E) 2.7 × 10^-2 mol L^-1, acidic

Question 35

Calculate the pH of a solution that contains 2.4 × 10^-5 mol L^-1 H₃O⁺ at 25 °C.

A) 2.40
B) 9.38
C) 4.62
D) 11.60
E) 4.17

Question 36

What is the pH of pure water at 40.0 °C if the K_w at this temperature is 2.92 × 10^-14?

A) 6.767
B) 0.465
C) 7.000
D) 7.233
E) 8.446

Question 37

Which of the following equilibria represents the second ionization step of H₃PO₄?

A) H₃PO₄(aq) + H₂O(l) ⇌ H₂PO₄^-(aq) + H₃O⁺(aq)
B) H₃PO₄(aq) + 2H₂O(l) ⇌ HPO₄^2-(aq) + 2H₃O⁺(aq)
C) H₂PO₄^-(aq) + H₂O(l) ⇌ HPO₄^2-(aq) + H₃O⁺(aq)
D) HPO₄^2-(aq) + H₂O(aq)⇌ PO₄^3-(aq) + H₃O⁺(aq)
E) H₃PO₄(aq) + 3H₂O(l) ⇌ PO₄^3-(aq) + 3H₃O⁺(aq)

Question 38

Which of the following is correct?

A) The smaller the acid ionization constant is, the more the acid ionizes and the stronger the acid.
B) The larger the acid ionization constant is, the less the acid ionizes and the weaker the acid.
C) The smaller the acid ionization constant is, the less the acid ionizes and the weaker the acid.
D) The smaller the acid ionization constant is, the less the acid ionizes and the weaker its conjugate base is.
E) The smaller the acid ionization constant is, the more the acid ionizes and the weaker the acid.

Question 39

Calculate the concentration of H₃O⁺ in a solution that contains 5.5 × 10^-5 mol L^-1 OH⁻ at 25 °C. Also identify the solution as acidic, basic, or neutral.

A) 1.8 × 10^-10 mol L^-1, basic
B) 1.8 × 10^-10 mol L^-1, acidic
C) 5.5 × 10^-10 mol L^-1, neutral
D) 9.2 × 10^-1 mol L^-1, acidic
E) 9.2 × 10^-1 mol L^-1, basic

Question 40

Which of the following is a weak acid?

A) HClO₄
B) H₂SO₄
C) HCl
D) HCO₂H
E) HNO₃

Question 41

Find the percent ionization of a 0.200 mol L^-1 solution of formic acid. The K_a of formic acid is 1.8 × 10^-4.

A) 3.0%
B) 2.0%
C) 1.0%
D) 3.5%
E) 4.6%

Question 42

Determine the [H₃O⁺] in a 0.265 mol L^-1 HClO solution. The K_a of HClO is 2.9 × 10^-8.

A) 1.1 × 10^-10 mol L^-1
B) 7.7 × 10^-9 mol L^-1
C) 1.3 × 10^-6 mol L^-1
D) 4.9 × 10^-4 mol L^-1
E) 8.8 × 10^-5 mol L^-1

Question 43

Find the percent ionization of a 0.265 mol L^-1 HClO solution. The K_a of HClO is 2.9 × 10^-8.

A) 0.0331%
B) 0.0551%
C) 1.12%
D) 3.65%
E) 3.32%

Question 44

Determine the pH of a 0.461 mol L^-1 C₆H₅CO₂H solution if the K_a of C₆H₅CO₂H is 6.5 × 10^-5.

A) 2.26
B) 4.52
C) 11.74
D) 9.48
E) 5.48

Question 45

Calculate the pOH of an aqueous solution with a pH of 9.85 at 25 °C.

A) 2.15
B) 3.15
C) 4.15
D) 5.15
E) 4.00

Question 46

Calculate the hydronium ion concentration in an aqueous solution with a pH of 9.85 at 25 °C.

A) 7.1 × 10^-5 mol L^-1
B) 4.2 × 10^-10 mol L^-1
C) 8.7 × 10^-10 mol L^-1
D) 6.5 × 10^-5 mol L^-1
E) 1.4 × 10^-10 mol L^-1

Question 47

Which of the following acids is the strongest? The acid is followed by its K_a value.

A) HF, 3.5 × 10^-4
B) HCN, 4.9 × 10^-10
C) HNO₂, 4.6 × 10^-4
D) HCHO₂, 1.8 × 10^-4
E) HClO₂, 1.1 × 10^-2

Question 48

The pH of a solution is 5.67 at 25 °C. Calculate the pOH of this solution at 25 °C.

A) 2.40
B) 8.33
C) 4.88
D) 11.4
E) 12.7

Question 49

Determine the K_a of an acid whose 0.294 mol L^-1 solution has a pH of 2.80.

A) 1.2 × 10^-5
B) 8.5 × 10^-6
C) 2.7
D) 4.9 × 10^-7
E) 5.4 × 10^-3

Question 50

The pH of a solution is 9.12 at 25 °C. Calculate the pOH of this solution at 25 °C.

A) 2.40
B) 8.33
C) 4.88
D) 11.4
E) 12.7

Question 51

Determine the pH of a 0.00598 mol L^-1 HClO₄ solution.

A) 1.777
B) 6.434
C) 7.566
D) 2.223
E) 3.558

Question 52

The pH of a solution is 2.62 at 25 °C. Calculate the pOH of this solution at 25 °C.

A) 2.40
B) 8.33
C) 4.88
D) 11.4
E) 12.7

Question 53

Which of the following acids is the weakest? The acid is followed by its K_a value.

A) CH₃COOH, 1.8 × 10^-5
B) HIO, 2.3 × 10^-11
C) HBrO, 2.3 × 10^-9
D) HClO, 2.9 × 10^-8
E) C₆H₅COOH, 6.3 × 10^-5

Question 54

Determine the pH of a 0.023 mol L^-1 HNO₃ solution.

A) 12.36
B) 3.68
C) 1.64
D) 2.30
E) 2.49

Question 55

Find the percent ionization of a 0.400 mol L^-1 solution of formic acid. The K_a of formic acid is 1.8 × 10^-4.

A) 3.4%
B) 2.1%
C) 1.1%
D) 3.5%
E) 4.6%

Question 56

Calculate the pOH of a solution that contains 2.4 × 10^-5 mol L^-1 H₃O⁺ at 25 °C.

A) 2.40
B) 9.38
C) 4.62
D) 11.60
E) 4.17

Question 57

Calculate the pH of a solution that contains 7.8 × 10^-6 mol L^-1 OH⁻ at 25 °C.

A) 1.28
B) 5.11
C) 12.72
D) 8.89
E) 9.64

Question 58

Calculate the hydroxide ion concentration in an aqueous solution with a pH of 4.33 at 25 °C.

A) 2.1 × 10^-10 mol L^-1
B) 9.7 × 10^-10 mol L^-1
C) 4.7 × 10^-5 mol L^-1
D) 3.8 × 10^-5 mol L^-1
E) 6.3 × 10^-6 mol L^-1

Question 59

Calculate the hydroxide ion concentration in an aqueous solution with a pH of 9.85 at 25 °C.

A) 7.1 × 10^-5 mol L^-1
B) 4.2 × 10^-10 mol L^-1
C) 8.7 × 10^-10 mol L^-1
D) 6.5 × 10^-5 mol L^-1
E) 1.4 × 10^-10 mol L^-1

Question 60

Find the percent ionization of a 0.337 mol L^-1 HF solution. The K_a for HF is 3.5 × 10^-4.

A) 1.1%
B) 1.2 × 10^-2%
C) 3.2%
D) 3.5 × 10^-2%
E) 4.7%

Question 61

Determine the pH of a 0.741 mol L^-1 KOH solution at 25 °C.

A) 0.13
B) 13.87
C) 0.17
D) 12.65
E) 11.88

Question 62

Determine the pOH of a 0.116 mol L^-1 Ba(OH)₂ solution at 25 °C.

A) 8.62
B) 13.06
C) 13.37
D) 0.63
E) 12.56

Question 63

Which of the following is a weak base?

A) NH(CH₃)₂
B) N₂
C) NaOH
D) CH₂CH₂
E) Ca(OH)₂

Question 64

Determine the pH of a 0.188 mol L^-1 NH₃ solution at 25 °C. The K_b of NH₃ is 1.76 × 10^-5.

A) 5.480
B) 2.740
C) 8.520
D) 11.260
E) 12.656

Question 65

Which of the following bases is the strongest? The base is followed by its K_b.

A) (CH₃CH₂)₂NH, 8.6 × 10^-4
B) CH₃NH₂, 4.4 × 10^-4
C) C₆H₅NH₂, 4.0 × 10^-10
D) NH₃, 1.76 × 10^-5
E) C₅H₅N, 1.7 × 10^-9

Question 66

Determine the pOH of a 0.188 mol L^-1 NH₃ solution at 25 °C. The K_b of NH₃ is 1.76 × 10^-5.

A) 5.480
B) 2.740
C) 8.520
D) 11.260
E) 12.656

Question 67

Determine the [OH^-] concentration of a 0.741 mol L^-1 KOH solution at 25 °C.

A) 1.34 × 10^-13 mol L^-1
B) 1.34 × 10^-14 mol L^-1
C) 0.741 mol L^-1
D) 7.41 mol L^-1
E) 7.41 × 10^-13 mol L^-1

Question 68

Determine the pOH in a 0.235 mol L^-1 NaOH solution.

A) 13.76
B) 0.24
C) 13.37
D) 0.63
E) 12

Question 69

Determine the [OH⁻] concentration in a 0.235 mol L^-1 NaOH solution.

A) 4.25 × 10^-14 mol L^-1
B) 0.470 mol L^-1
C) 2.13 × 10^-14 mol L^-1
D) 0.198 mol L^-1
E) 0.235 mol L^-1

Question 70

Calculate the pH of a 0.200 mol L^-1 solution of formic acid, K_a = 1.8 × 10^-4.

A) 3.84
B) 2.22
C) 4.62
D) 1.97
E) 3.07

Question 71

Determine the pOH of a 0.051 mol L^-1 Sr(OH)₂ solution at 25 °C.

A) 8.62
B) 13.01
C) 13.37
D) 0.991
E) 12.56

Question 72

Which of the following bases is the weakest? The base is followed by its K_b value.

A) HOCH₂CH₂NH₂, 3.2 × 10^-5
B) NH₃, 1.76 × 10^-5
C) C₅H₅N, 1.7 × 10^-9
D) (CH₃CH₂)₃N, 5.2 × 10^-4
E) CH₃CH₂NH₂, 5.6 × 10^-4

Question 73

Determine the [OH⁻] concentration in a 0.169 mol L^-1 Ca(OH)₂ solution.

A) 0.338 mol L^-1
B) 0.169 mol L^-1
C) 5.92 × 10^-14 mol L^-1
D) 2.96 × 10^-14 mol L^-1
E) 0.298 mol L^-1

Question 74

Determine the pH of a 0.116 mol L^-1 Ba(OH)₂ solution at 25 °C.

A) 8.62
B) 13.06
C) 13.37
D) 0.63
E) 12.56

Question 75

Which of the following is a strong base?

A) Cl^-
B) NH₃
C) CH₃OH
D) NO₃⁻
E) KOH

Question 76

Determine the pH of a 0.051 mol L^-1 Sr(OH)₂ solution at 25 °C.

A) 8.62
B) 13.01
C) 13.37
D) 0.991
E) 12.56

Question 77

Determine the [OH^-] concentration of a 0.116 mol L^-1 Ba(OH)₂ solution at 25 °C.

A) 4.310 × 10^-14 mol L^-1
B) 0.116 mol L^-1
C) 0.232 mol L^-1
D) 8.62 × 10^-14 mol L^-1
E) 0.058 mol L^-1

Question 78

Determine the pH in a 0.435 mol L^-1 LiOH solution.

A) 13.6
B) 0.24
C) 13.37
D) 0.6
E) 12

Question 79

Determine the pH in a 0.235 mol L^-1 NaOH solution.

A) 13.76
B) 0.24
C) 13.37
D) 0.63
E) 12

Question 80

Determine the pOH of a 0.741 mol L^-1 KOH solution at 25 °C.

A) 0.13
B) 13.87
C) 0.17
D) 12.65
E) 11.88