Chapter 15 1 A weak base is composed of a cation and an anion with

Chemistry: A Molecular Approach, 2e (Tro)

Chapter 15 Acids and Bases

Multiple Choice Questions

1) ________ is found in carbonated beverages due to the reaction of carbon dioxide with water.

A) CH3COOH

B) H2CO3

C) HCOOH

D) C6H5COOH

E) CH3CH2COOH

2) Which of the following species is amphoteric?

A) CO32-

B) HF

C) NH4⁺

D) HPO42-

E) None of the above are amphoteric.

3) What is the conjugate acid of HCO3⁻ ?

A) H3O+

B) H2O

C) CO32-

D) OH⁻

E) H2CO3

4) What is the conjugate base of H2PO4⁻ ?

A) HPO42-

B) PO43-

C) H3PO4

D) H3O+

E) OH⁻

5) Which of the following is NOT a conjugate acid-base pair?

A) NH4+/NH3

B) H3O⁺/OH⁻

C) H2SO3/HSO3⁻

D) C2H3O2⁻/HC2H3O2

E) All of the above are conjugate acid-base pairs.

6) Identify the weak diprotic acid.

A) CH3COOH

B) HCOOH

C) H3PO4

D) H2SO4

E) H2CO3

7) Identify the weak diprotic acid.

A) HNO3

B) H3PO4

C) H2SO3

D) HClO4

E) H2SO4

8) Give the characteristics of a strong acid.

A) ionizes completely in aqueous solutions

B) has equilibrium far to the right

C) has a polar bond

D) has a weaker bond to hydrogen

E) all of the above

9) The stronger the acid, then which of the following is TRUE?

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) None of the above.

10) Place the following in order of increasing acid strength.

HBrO2 HBrO3 HBrO HBrO4

A) HBrO2 < HBrO4 < HBrO < HBrO3

B) HBrO < HBrO2 < HBrO3 < HBrO4

C) HBrO2 < HBrO3 < HBrO4 < HBrO

D) HBrO4 < HBrO2 < HBrO3 < HBrO

E) HBrO < HBrO4 < HBrO3 < HBrO2

11) 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) None of the above statements are true.

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

A) HCl

B) HClO4

C) HNO3

D) HCN

E) HI

13) Which of the following solutions would have the highest pH? Assume that they are all 0.10 M in

acid at 25∘C. The acid is followed by its Ka 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

14) Which of the following is TRUE?

A) A neutral solution contains [H2O] = [H3O⁺]

B) An 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) None of the above are true.

15) What is the concentration of hydroxide ions in pure water at 30.0∘C, if Kw at this temperature is

1.47 × 10-14?

A) 1.00 × 10-7 M

B) 1.30 × 10-7 M

C) 1.47 × 10-7 M

D) 8.93 × 10-8 M

E) 1.21 × 10-7 M

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

A) 6.767

B) 0.465

C) 7.000

D) 7.233

E) 8.446

17) What is the Kw 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) There is not enough information to calculate the Kw.

18) Calculate the concentration of H3O⁺ in a solution that contains 5.5 × 10-5 M OH⁻ at 25°C. Identify

the solution as acidic, basic, or neutral.

A) 1.8 × 10-10 M, basic

B) 1.8 × 10-10 M, acidic

C) 5.5 × 10-10 M, neutral

D) 9.2 × 10-1 M, acidic

E) 9.2 × 10-1 M, basic

19) Calculate the concentration of OH⁻ in a solution that contains 3.9 x 10-4 M H3O⁺ at 25°C. Identify

the solution as acidic, basic, or neutral.

A) 2.6 × 10-11 M, acidic

B) 2.6 × 10-11 M, basic

C) 3.9 × 10-4 M, neutral

D) 2.7 × 10-2 M, basic

E) 2.7 × 10-2 M, acidic

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

A) 7.1 × 10-5 M

B) 4.2 × 10-10 M

C) 8.7 × 10-10 M

D) 6.5 × 10-5 M

E) 1.4 × 10-10 M

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

A) 7.1 × 10-5 M

B) 4.2 × 10-10 M

C) 8.7 × 10-10 M

D) 6.5 × 10-5 M

E) 1.4 × 10-10 M

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

A) 7.1 × 10-5 M

B) 4.2 × 10-10 M

C) 8.7 × 10-10 M

D) 6.5 × 10-5 M

E) 1.4 × 10-10 M

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

A) 7.1 × 10-5 M

B) 4.2 × 10-10 M

C) 8.7 × 10-10 M

D) 6.5 × 10-5 M

E) 1.4 × 10-10 M

24) Determine the pH of a 0.023 M HNO3 solution.

A) 12.36

B) 3.68

C) 1.64

D) 2.30

E) 2.49

25) Determine the pH of a 0.00598 M HClO4 solution.

A) 11.777

B) 6.434

C) 7.566

D) 2.223

E) 3.558

26) Determine the pOH of a 0.00598 M HClO4 solution.

A) 11.777

B) 6.434

C) 7.566

D) 2.223

E) 3.558

27) Calculate the pH of a solution that contains 7.8 x 10-6 M OH⁻ at 25°C.

A) 1.28

B) 5.11

C) 12.72

D) 8.89

E) 9.64

28) Calculate the pOH of a solution that contains 7.8 x 10-6 M OH⁻ at 25°C.

A) 1.28

B) 5.11

C) 12.72

D) 8.89

E) 9.64

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

A) 2.1 × 10-10 M

B) 9.7 × 10-10 M

C) 4.7 × 10-5 M

D) 3.8 × 10-5 M

E) 6.3 × 10-6 M

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

A) 2.1 × 10-10 M

B) 9.7 × 10-10 M

C) 4.7 × 10-5 M

D) 3.8 × 10-5 M

E) 6.3 × 10-6 M

31) Calculate the hydronium ion concentration in an aqueous solution with a pOH of 4.33 at 25°C.

A) 2.1 × 10-10 M

B) 9.7 × 10-10 M

C) 4.7 × 10-5 M

D) 3.8 × 10-5 M

E) 6.3 × 10-6 M

32) Determine the [H3O⁺] in a 0.265 M HClO solution. The Ka of HClO is 2.9 × 10-8.

A) 1.1 × 10-10 M

B) 7.7 × 10-9 M

C) 1.3 × 10-6 M

D) 4.9 × 10-4 M

E) 8.8 × 10-5 M

33) Find the percent ionization of a 0.337 M HF solution. The Ka 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 %

34) Determine the pH of a 0.461 M C6H5CO2H M solution if the Ka of C6H5CO2H is 6.5 x 10-5.

A) 2.26

B) 4.52

C) 11.74

D) 9.48

E) 5.48

35) Determine the Ka of an acid whose 0.294 M 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

36) Which of the following bases is the STRONGEST? The base is followed by its Kb.

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

37) Which of the following bases is the WEAKEST? The base is followed by its Kb 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) Since these are all weak bases, they have the same strength.

38) Determine the pH in a 0.235 M NaOH solution.

A) 13.76

B) 0.24

C) 13.37

D) 0.63

E) 12

39) Determine the pOH in a 0.235 M NaOH solution.

A) 13.76

B) 0.24

C) 13.37

D) 0.63

E) 12

40) Determine the [OH⁻] concentration in a 0.169 M Ca(OH)2 solution.

A) 0.338 M

B) 0.169 M

C) 5.92 × 10-14 M

D) 2.96 × 10-14 M

E) 0.298 M

41) Determine the [OH–] concentration of a 0.741 M KOH solution at 25°C.

A) 1.34 x 10-13 M

B) 1.34 x 10-14 M

C) 0.741 M

D) 7.41 M

E) none of the above

42) Determine the pH of a 0.188 M NH3 solution at 25°C. The Kb of NH3 is 1.76 × 10-5.

A) 5.480

B) 2.740

C) 8.520

D) 11.260

E) 12.656

43) Determine the pOH of a 0.188 M NH3 solution at 25°C. The Kb of NH3 is 1.76 × 10-5.

A) 5.480

B) 2.740

C) 8.520

D) 11.260

E) 12.656

44) Determine the pH of a 0.227 M C5H5N solution at 25°C. The Kb of C5H5N is 1.7 × 10-9.

A) 4.59

B) 9.41

C) 4.71

D) 10.14

E) 9.29

45) Determine the pOH of a 0.227 M C5H5N solution at 25°C. The Kb of C5H5N is 1.7 × 10-9.

A) 4.59

B) 9.41

C) 4.71

D) 10.14

E) 9.29

46) List an ingredient that is in antacid.

A) Al(OH)3

B) Mg(OH)2

C) CaCO3

D) all of the above

E) none of the above

47) Which one of the following will form a basic solution in water?

A) NaC2H3O2

B) LiCN

C) KClO2

D) LiBrO

E) All of the above will form basic solutions.

48) Determine the Kb for CN⁻ at 25°C. The Ka for HCN is 4.9 × 10-10.

A) 4.9 × 10-14

B) 2.3 × 10-9

C) 1.4 × 10-5

D) 2.0 × 10-5

E) 3.7 × 10-7

49) Determine the Ka for CH3NH3⁺ at 25°C. The Kb for CH3NH2 is 4.4 × 10-4.

A) 3.1 × 10-10

B) 6.8 × 10-11

C) 5.6 × 10-10

D) 2.3 × 10-3

E) 2.3 × 10-11

50) Determine the pH of a 0.62 M NH4NO3 solution at 25°C. The Kb for NH3 is 1.76 × 10-5.

A) 2.48

B) 9.27

C) 11.52

D) 4.73

E) 9.45

51) Determine the pH of a 0.22 M NaF solution at 25°C. The Ka of HF is 3.5 × 10-5.

A) 10.20

B) 5.10

C) 8.90

D) 11.44

E) 2.56

52) In a triprotic acid, which Ka has the highest value?

A) Ka1

B) Ka2

C) Ka3

D) Kb1

E) Kb2

53) Determine the pH of a 0.18 M H2CO3 solution. Carbonic acid is a diprotic acid whose

Ka1 = 4.3 × 10-7 and Ka2 = 5.6 × 10-11.

A) 11.00

B) 10.44

C) 5.50

D) 4.31

E) 3.56

54) Determine the pH of a solution that is 0.15 M HClO2 (Ka = 1.1 x 10-2) and 0.15 M HClO

(Ka = 2.9 × 10-8).

A) 4.18

B) 9.82

C) 12.55

D) 1.39

E) 3.55

55) Determine the concentration of CO32- ions in a 0.18 M H2CO3 solution. Carbonic acid is a diprotic

acid whose Ka1 = 4.3 × 10-7 and Ka2 = 5.6 × 10-11.

A) 2.8 × 10-4 M

B) 3.2 × 10-6 M

C) 5.6 × 10-11 M

D) 4.3 × 10-7 M

E) 6.9 × 10-8 M

56) Identify the strongest acid.

A) H2O

B) H2S

C) H2Se

D) H2Te

E) not enough information is available

57) Identify the weakest acid.

A) HF

B) HCl

C) HBr

D) HI

E) not enough information is available

58) Acid rain consists primarily of ________.

A) nitric and sulfuric acids

B) sulfuric acid

C) nitric acid

D) acetic acid

E) benzoic acid

Algorithmic Questions

1) The stomach excretes ________ to kill microorganisms and to activate enzymes that break down

food.

A) CH3COOH

B) HF

C) LiHCO3

D) HCl

E) HNO3

2) Identify the acid that is in car batteries.

A) H2SO4

B) HNO3

C) H2CO3

D) CH3COOH

E) HCl

3) Identify the acid that is in vinegar.

A) H2SO4

B) HNO3

C) Na2CO3

D) CH3COOH

E) HF

4) Identify the base that is in baking soda.

A) RbOH

B) NaOH

C) NaHCO3

D) Li2CO3

E) NH3

5) Identify the base that is in Drano.

A) KOH

B) NaOH

C) KHCO3

D) Na2CO3

E) NH3

6) When dissolved in water, which compound is generally considered to be an Arrhenius acid?

A) CH3CO2H

B) NaOH

C) Na2CO3

D) CH3CH2OH

7) Which of the following is an Arrhenius acid?

A) H2SO4

B) LiOH

C) NH2CH3

D) CH3CCl3

E) More than one of these is an Arrhenius acid.

8) Which of the following is an Arrhenius base?

A) CH3CO2H

B) LiOH

C) CH3OH

D) NaBr

E) More than one of these compounds is an Arrhenius base.

9) Which Br∅nsted-Lowry acid is not considered to be a strong acid in water?

A) HI

B) HBr

C) H2SO3

D) H NO3

10) Which of the following is a Br∅nsted-Lowry acid?

A) NH4+

B) CCl4

C) NH2–

D) NH3

E) Br2

11) Which of the following is a Br∅nsted-Lowry base?

A) CBr4

B) HCN

C) NH3

D) Cl2

E) None of the above are Br∅nsted-Lowry bases.

12) Identify the diprotic acid.

A) HNO3

B) HI

C) CH3COOH

D) H2SO4

E) HBrO4

13) Identify the triprotic acid.

A) HNO3

B) H3PO4

C) H2CO3

D) HFO4

E) H2SO4

14) Which of the following is a STRONG acid?

A) C6H5CO2H

B) HCN

C) HClO4

D) NH4+

E) H2O

15) Which of the following is a WEAK acid?

A) HClO4

B) H2SO4

C) HBr

D) HCN

E) HNO3