Deck 13: Acids and Bases

Question 1

If the pH of a solution is greater than 7,the solution is

A) acidic.
B) basic.
C) amphiprotic.
D) neutral.
E) in equilibrium.

Answer 1

basic.

Question 2

What is the conjugate base of HClO₂?

A) H⁺
B) H−
C) ClO₂⁺
D) ClO⁺
E) ClO₂−

Answer 2

ClO₂−

Question 3

The hydronium ion concentration in a sample of lemon juice is 3.2 × 10−³ M.What is the pH of the lemon juice?

A) 1.06
B) 2.01
C) 2.49
D) 5.21
E) 11.72

Answer 3

2.49

Question 4

Which of the following chemical reactions represents the ionization of water?

A) 2H₂O(l) ? 2H₂(g)+ O₂(g)
B) H₂O(l) ? H₂O?(aq)
C) H₂O(l) ? H₂O⁺(aq)+ e?
D) H₂O(l) ? H⁺(aq)+ OH?(aq)
E) H⁺(aq)+ OH?(aq) ? H₂O(l)

Question 5

What is the conjugate acid of ammonia?

A) H⁺
B) H−
C) NH₄⁺
D) NH₃
E) NH₂−

Question 6

Seawater has a hydroxide ion concentration of 2.0 × 10−⁶ M.What is the pH of seawater?

A) −8.30
B) 5.70
C) 6.99
D) 7.53
E) 8.30

Question 7

What is the conjugate base of water?

A) H⁺
B) O²⁻
C) OH−
D) H₂O
E) H₃O⁺

Question 8

If the H⁺ concentration in a carbonated beverage is 4.7 × 10−⁵ M,what is the OH− concentration? (K_w = 1.0 × 10−¹⁴)

A) 4.7 × 10−¹⁹ M
B) 2.1 × 10−¹⁰ M
C) 5.3 × 10−⁵ M
D) 2.1 × 104 M
E) 4.7 × 109 M

Question 9

All of the following species are strong acids EXCEPT

A) HClO₄.
B) HBr.
C) H₂SO₄.
D) HF.
E) HI.

Question 10

The pH of a human blood sample is 7.30.What is concentration of OH− in blood?

A) 5.01 × 10−⁸ M
B) 2.0 × 10−⁷ M
C) 7.3 × 10−⁷ M
D) 5.01 × 10−⁵ M
E) 2.0 × 10⁷ M

Question 11

A species that can either accept or donate a proton is called

A) a Brønsted-Lowry compound.
B) a Lewis base.
C) an Arrhenius acid.
D) amphiprotic.
E) a conjugate pair.

Question 12

If the OH− concentration in a bottle of an ammonia based cleaner is 3.8 × 10−² M,what is the H⁺ concentration? (K_w = 1.0 × 10−¹⁴)

A) 3.8 × 10−¹⁶ M
B) 2.6 × 10−¹³ M
C) 6.8 × 10−² M
D) 2.6 × 101 M
E) 3.8 × 1012 M

Question 13

What is the correct expression for the calculation of pH?

A) pH = log[1.0 × 10−¹⁴]
B) pH = −log([H⁺][OH−])
C) pH = log[OH−]
D) pH = −log[OH−]
E) pH = −log[H⁺]

Question 14

What is the conjugate acid of potassium hydrogen phosphate,K₂HPO₄?

A) H₃PO₄
B) H₂PO₄−
C) HPO₄²⁻
D) K⁺
E) OH−

Question 15

What is the pH of 6.5 × 10^-5 M KOH(aq)at 25°C?

A) -4.19
B) 1.54
C) 4.19
D) 9.81
E) 12.46

Question 16

What is the H₃O⁺ concentration of an aqueous solution with a pH of 8.77?

A) 1.7 × 10^-9 M
B) 5.9 × 10^-6 M
C) 1.6 × 10^-4 M
D) 5.23 M
E) 5.9 × 10⁸ M

Question 17

All of the following species are strong bases EXCEPT

A) NaOH.
B) KOH.
C) Mg(OH)₂.
D) Sr(OH)₂.
E) RbOH.

Question 18

All of the following species are amphiprotic EXCEPT

A) H₂O.
B) HSO₄−.
C) HPO₄²⁻.
D) SO₄²⁻.
E) H₂PO₄−.

Question 19

If the H⁺ concentration is less than 1.0 × 10−⁷ M,the solution is

A) basic.
B) acidic.
C) neutral.
D) amphiprotic.
E) in equilibrium.

Question 20

Which of the following equilibrium constant expressions represents the ionization of water?

A) $K_{W}=\left[\mathrm{H}^{+}\right]\left[\mathrm{OH}^{-}\right]$
B) $K_{\mathrm{W}}=\frac{\left[\mathrm{H}^{+}\right]}{\left[\mathrm{OH}^{-}\right]}$
C) $K_{w}=\frac{\left[\mathrm{OH}^{-}\right]}{\left[\mathrm{H}^{+}\right]}$
D) K_W = ?log[H⁺]
E) K_W = ?log[OH?]

Question 21

Which of the following solutions will have a pH of 11.0?

A) 1 × 10¹¹ M Sr(OH)₂
B) 1 × 10−¹¹ M NH₃
C) 1 × 10−¹¹ M HCl
D) 1 × 10−³ M NH₄⁺
E) 1 × 10−³ M NaOH

Question 22

What is the pH of a solution prepared by diluting 0.40 mol HNO₃(aq)to a volume of 225 mL?

A) −0.25
B) 0.25
C) 0.40
D) 2.75
E) 7.50

Question 23

What is the conjugate base of [Fe(H₂O)₆]³⁺(aq)?

A) H₃O⁺
B) [Fe(H₂O)₆]²⁺
C) [Fe(H₂O)₅H₃O]⁴⁺
D) [Fe(H₂O)₅OH]²⁺
E) [Fe(H₂O)₅]³⁺

Question 24

The conjugate acid of a weak base is

A) amphiprotic.
B) a weak base.
C) a weak acid.
D) a strong acid.
E) a strong base.

Question 25

Which of the following chemical equations corresponds to the base ionization constant,K_b,for hydrogen sulfite ion (HSO₃^-)?

A) HSO₃^-(aq)+ H₂SO₃(aq) $\rightleftharpoons$ 2 H₂SO₃(aq)
B) HSO₃^-(aq)+ H₂O(l) $\rightleftharpoons$ SO₃^2-(aq)+ H₃O⁺(aq)
C) HSO₃^-(aq)+ OH^-(aq) $\rightleftharpoons$ SO₃^2-(aq)+ H₂O(l)
D) HSO₃^-(aq)+ H₃O⁺(aq) ? H₂SO₃(aq)+ H₂O(l)
E) HSO₃^-(aq)+ H₂O(l) ? H₂SO₃(aq)+ OH^-(aq)

Question 26

A solution of 0.25 mol HF diluted to 1.0 L has a hydronium ion concentration of 1.3 × 10−² M.What is the percent ionization of HF?

A) 0.80 %
B) 1.3%
C) 4.2%
D) 5.2%
E) 31%

Question 27

A solution of 0.10 M aluminum nitrate has a pH close to 3.0.Which chemical equation explains the acidic pH of the solution?

A) Al³⁺(aq)+ 3OH?(aq) ? Al(OH)₃(s)+ 3H₃O⁺(aq)
B) Al(H₂O)₆³⁺(aq)+ H₂O(l) ? Al(H₂O)₅(OH)²⁺(aq)+ H₃O⁺(aq)
C) Al(NO₃)₃(s)+ 3H₂O(l) ? Al(OH)₃(s)+ 3HNO₃(s)
D) HNO₃(aq)+ H₂O(l) ? NO₃?(aq)+ H₃O⁺(aq)
E) NO₃?(aq)+ H₂O(l) ? H₂O + HNO₃(aq)

Question 28

The pH of 0.400 M sodium nitrite,NaNO₂,is 8.42.What is the K_b for this base?

A) 1.7 × 10−¹¹
B) 3.6 × 10−¹⁰
C) 3.8 × 10−⁹
D) 9.5 × 10−⁹
E) 8.8 × 10−⁷

Question 29

Which of the following mathematical equations corresponds to the acid dissociation constant (K_a)?

A) $K_{\mathrm{a}}=\frac{\left[\mathrm{H}^{+}\right]\left[\mathrm{OH}^{-}\right]}{[\mathrm{HB}]}$
B) $K_{\mathrm{a}}=\frac{\left[\mathrm{H}^{+}\right][\mathrm{HB}]}{\left[\mathrm{B}^{-}\right]}$
C) $K_{\mathrm{a}}=\frac{[\mathrm{HB}]\left[\mathrm{B}^{-}\right]}{\left[\mathrm{H}^{+}\right]}$
D) $K_{\mathrm{a}}=\frac{\left[\mathrm{B}^{-}\right][\mathrm{HB}]}{\left[\mathrm{H}^{+}\right]}$
E) $K_{\mathrm{a}}=\frac{\left[\mathrm{H}^{+}\right]\left[\mathrm{B}^{-}\right]}{[\mathrm{HB}]}$

Question 30

Which of the following solutions will have a pH of 3.0?

A) 1 × 10−³ M CH₃CO₂H
B) 1 × 10−³ M NH₃
C) 1 × 10−³ M NH₄⁺
D) 1 × 10−³ M HI
E) Answers b and c are correct.

Question 31

The pH of 0.350 M benzoic acid,HC₇H₅O₂,is 2.32.What is the pK_a for this acid?

A) 0.350
B) 1.38
C) 1.79
D) 2.32
E) 4.18

Question 32

An aqueous solution with a pH of 2.00 is diluted from 1.0 L to 3.0 L.What is the pH of the diluted solution?

A) 0.67
B) 2.00
C) 2.48
D) 4.33
E) 6.00

Question 33

The anions derived from strong acids are

A) spectator ions.
B) strong bases.
C) amphiprotic.
D) weak acids.
E) weak bases.

Question 34

Which of the following species is a weak base?

A) KOH
B) NH₄⁺
C) HF
D) H₃PO₄
E) CH₃CO₂−

Question 35

The acid equilibrium constant (K_a)for ammonium chloride refers to which of the following chemical reactions?

A) NH₄⁺(aq)+ H₃O⁺(aq) ? NH₅²⁺(aq)+ H₂O(l)
B) NH₄⁺(aq)+ H₂O(l) ? NH₃(aq)+ H₃O⁺(aq)
C) NH₄⁺(aq)+ OH?(aq) ? NH₃(aq)+ H₂O(l)
D) NH₃(aq)+ H₂O(l) ? NH₄⁺(aq)+ OH?(aq)
E) NH₃(aq)+ H₃O⁺(aq) ? NH₄⁺(aq)+ H₂O(l)

Question 36

The pH of aqueous 0.10 M pyridine (C₅H₅N)ion is 9.09.What is the K_b of this base?

A) 8.0 × 10^-10
B) 1.5 × 10^-9
C) 9.0 × 10^-6
D) 1.6 × 10^-5
E) 1.2 × 10^-5

Question 37

At 50°C,the water ionization constant,K_w,is 5.48 × 10^-14.What is the H₃O⁺ concentration in neutral water at this temperature?

A) 3.00 × 10^-27 M
B) 2.74 × 10^-14 M
C) 5.48 × 10^-14 M
D) 2.34 × 10^-7 M
E) 1.01 × 10^-7 M

Question 38

The pH of aqueous 0.50 M hypobromous acid,HBrO,is 4.45.What is the K_a of this acid?

A) 2.5 × 10^-9
B) 5.0 × 10^-9
C) 3.4 × 10^-7
D) 3.5 × 10^-5
E) 7.1 × 10^-5

Question 39

What is the pH of 0.26 M ammonium ion?
NH₄⁺(aq)+ H₂O(l) ? NH₃(aq)+ H₃O⁺(aq)
K_a = 5.6 × 10?¹⁰

A) 3.87
B) 4.33
C) 4.75
D) 4.92
E) 9.25

Question 40

Which of the following chemical reactions corresponds to the generic form of the base dissociation constant (K_b)?

A) HB(aq)+ OH?(aq) ? B?(aq)+ H₂O(l)
B) 2H₂O(l) ? H₃O⁺(aq)+ OH?(aq)
C) HB(aq)+ H₂O(l) ? B?(aq)+ H₃O⁺(aq)
D) B?(aq)+ H₂O(l) ? HB(aq)+ OH?(aq)
E) B?(aq)+ H₃O⁺(aq) ? HB(aq)+ H₂O(l)

Question 41

Determine the equilibrium constant for the reaction HF(aq)+ NH₃(aq) ? F?(aq)+ NH₄⁺(aq)
Given the equilibrium constants for the following reactions.
$\begin{array}{ll}\mathrm{HF}(a q)+\mathrm{H}_{2} \mathrm{O}(l) \rightleftharpoons \mathrm{F}-(a q)+\mathrm{H}_{3} \mathrm{O}^{-}(a q) & K_{\mathrm{a}}=6.9 \times 10^{-4} \\\mathrm{NH}_{3}(a q)+\mathrm{H}_{2} \mathrm{O}(l) \rightleftharpoons \mathrm{NH}_{4}^{+}(a q)+\mathrm{OH}-(a q) & K_{\mathrm{b}}=1.8 \times 10^{-5} \\2 \mathrm{H}_{2} \mathrm{O} \rightleftharpoons \mathrm{OH}-(a q)+\mathrm{H}_{3} \mathrm{O}^{+}(a q) & K_{\mathrm{W}}=1.0 \times 10^{-14}\end{array}$

A) 1.2 × 10?⁸
B) 1.2 × 10⁶
C) 8.1 × 10⁷
D) 1.0 × 10¹⁴
E) 3.8 × 10¹⁵

Question 42

What is the pH of 0.25 M aqueous acetate ion? (K_b of CH₃CO₂^- = 5.6 × 10^-10)

A) 4.32
B) 4.93
C) 9.07
D) 9.68
E) 13.40

Question 43

A salt solution can be acidic,basic,or neutral.When dissolved in water,which of the following salts will not affect the pH: KCl,FeCl₃,NaNO₃,CaCO₃,LiF,and NH₄Br?

A) KCl and FeCl₃
B) KCl,FeCl₃ and NaNO₃
C) CaCO₃ and LiF
D) KCl and NaNO₃
E) CaCO₃,LiF,and NH₄Br

Question 44

The K_a for hydrofluoric acid is 6.9 × 10−⁴.What is K_b for fluoride ion?

A) 1.0 × 10−¹⁴
B) 1.4 × 10−¹¹
C) 7.4 × 10−⁹
D) 1.0 × 10−⁷
E) 6.9 × 10¹⁰

Question 45

What is the pH of 1.0 M sulfurous acid? (K_a1 = 1.7 × 10−²,K_a2 = 6.0 × 10−⁸)

A) −0.88
B) 0.00
C) 0.12
D) 0.13
E) 0.91

Question 46

Hydrogen sulfate ion,HSO₄−,has an acid dissociation constant of 1.0 × 10−².What is the pH of 0.45 M hydrogen sulfate?

A) 0.35
B) 1.21
C) 2.00
D) 2.19
E) 3.03

Question 47

Identify from the following list of molecules and ions those which behave as Lewis acids: NH₃,BCl₃,Fe³⁺.

A) NH₃ only
B) NH₃ and BCl₃
C) Fe³⁺ only
D) BCl₃,and Fe³⁺
E) NH₃,BCl₃,and Fe³⁺

Question 48

A salt solution can be acidic,basic,or neutral.When dissolved in water,which of the following salts will make the solution acidic: NaCl,Al₂(SO₄)₃,NaNO₃,Na₂CO₃,KF,and NH₄Br?

A) Al₂(SO₄)₃ and NH₄Br
B) Al₂(SO₄)₃,Na₂CO₃ and NH₄Br
C) Al₂(SO₄)₃ and NaNO₃
D) NaCl,NaNO₃ and NH₄Br
E) Na₂CO₃,KF,and NH₄Br

Question 49

All carboxylic acids contain the organic group(s)______ .

A) −CH₃
B) −NH₂
C) −OH
D) −COOH
E) both −NH₂ and −COOH

Question 50

All of the following statements concerning diprotic acids and bases are incorrect EXCEPT

A) K_a2 is larger than K_a1.
B) K_a1 is larger than K_a2.
C) K_a1 is equal to K_b2.
D) K_a1 + K_b2 equals K_w.
E) K_a1 + K_a2 equals K_w.

Question 51

Given the following equilibrium constants, K_a (HSO₄^-)= 1.2 × 10^-2
K_b (CH₃CO₂^-)= 5.6 × 10^-10
K_w = 1.00 × 10^-14
determine the equilibrium constant for the reaction below at 25°C.
HSO₄^-(aq)+ CH₃CO₂^-(aq) ? SO₄^2-(aq)+ CH₃CO₂H(aq)

A) 6.7 × 10^-12
B) 2.1 × 10^-7
C) 1.5 × 10^-3
D) 6.7 × 10²
E) 2.1 × 10⁷

Question 52

A salt solution can be acidic,basic,or neutral.When dissolved in water,which of the following salts will make the solution basic: KBr,MgCO₃,NaF,Na₂SO₄,and CrCl₃?

A) MgCO₃ and CrCl₃
B) KBr and Na₂SO₄
C) KBr,MgCO₃,and CrCl₃
D) MgCO₃,NaF,and Na₂SO₄
E) NaF,Na₂SO₄,and CrCl₃

Question 53

A Lewis acid is defined as a(n)

A) electron pair acceptor.
B) proton acceptor.
C) electron pair donor.
D) spectator ion.
E) proton acceptor..

Question 54

Ammonia is a weak base (K_b = 1.8 × 10−⁵).What is the pH of 1.2 M ammonia?

A) 2.33
B) 4.74
C) 9.26
D) 10.14
E) 11.67

Question 55

Lactic acid,HC₃H₅O₃,is found in sour milk.What is the pH of 0.30 M lactic acid? (K_a = 1.4 × 10−⁴)

A) 0.52
B) 1.07
C) 2.19
D) 4.00
E) 5.12

Question 56

Which of the following chemical equations corresponds to K_b1 for SO₃^2-?

A) HSO₃^-(aq)+ H₂O(l) ? H₂SO₃(aq)+ OH^-(aq)
B) SO₃^2-(aq)+ H₃O⁺(aq) ? HSO₃^-(aq)+ H₂O(l)
C) H₂SO₃(aq)+ OH^-(aq) ? HSO₃^-(aq)+ H₂O(l)
D) HSO₃^-(aq)+ OH^-(aq) ? SO₃^2-(aq)+ H₂O(l)
E) SO₃^2-(aq)+ H₂O(l) ? HSO₃^-(aq)+ OH^-(aq)

Question 57

Which of the following chemical equations corresponds to K_a3 for phosphoric acid,H₃PO₄?

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