CHEM 1312. Chapter 15. Acids and Bases (Homework) S

pg. 1 CHEM 1312. Chapter 15. Acids and Bases (Homework) S

CHEM 1312. Chapter 15. Acids and Bases (Homework) S

1. Identify the conjugate base of HPO42–.

A. H2O B. H2PO4

– C. H3PO4 D. PO4

3– E. OH–

2.

Identify the conjugate base of HSO4–.

A. OH–

B. H2SO4

C. H2O

D. H2SO3

E. SO42–

3. Identify the conjugate acid of HCO3–.

A. H2O B. CO3

2– C. H2CO3 D. CO2 E. H3O+

4. Which one of these statements about strong acids is true? A. All strong acids have H atoms bonded to electronegative oxygen atoms. B. Strong acids are 100% ionized in water. C. The conjugate base of a strong acid is itself a strong base. D. Strong acids are very concentrated acids. E. Strong acids produce solutions with a higher pH than weak acids.


5. The OH– concentration in a 7.5 10–3 M Ca(OH)2 solution is

A. 7.5 10–3 M.

B. 1.5 10–2 M.

C. 1.3 10–12 M.

D. 1.0 10–7 M.

E. 1.0 10–14 M.

6. Which of the following solutions is acidic? A. [OH-] = 1.0 x 10-7 M B. [OH-] > 1.0 x 10-7 M C. [OH-] = 1.0 x 10-10 M D. [H3O+] = 1.0 x 10-10 M E. [H3O+] < 1.0 x 10-7 M

7. Calculate the pH of a carbonated beverage in which the hydrogen ion concentration is 3.4 10–4 M. A. 2.34 B. 3.47 C. 6.01 D. 7.99 E. 10.53

8. Determine the pH of a KOH solution made by mixing 0.251 g KOH with enough water to make 1.0

102 mL of solution. A. 1.35 B. 2.35 C. 7.00 D. 11.65 E. 12.65

9. What is the pH of 10.0 mL of 0.0020 M HCl? A. 0.70 B. 2.70 C. 3.70 D. 5.70 E. 10.0


10. What is the pH of a 0.0055 M HA (weak acid) solution that is 8.2% ionized? A. 2.26 B. 3.35 C. 4.52 D. 8.21 E. 10.65

11. Calculate the hydrogen ion concentration in a solution of iced tea with lemon having a pH of 2.87.

A. 2.9 10–2 M

B. 5.7 10–2 M

C. 1.3 10–3 M

D. 2.9 10–3 M

E. 5.7 10–4 M

12. The pH of coffee is approximately 5.0. How many times greater is the [H+] in coffee than in neutral water? A. 200 B. 100 C. 5.0 D. 1.4 E. 0.01

13. A 5.5 L sample of a 0.25 M HNO3 solution is mixed with 1.2 L of a 0.34 M HCl solution. What is the pH of the mixture? A. 0.23 B. 0.57 C. 1.07 D. 0.50 E. 0.84


14.

Given the following Ka values, which anion is the strongest base?

A. HCO3

–

B. CO32–

C. HC2O4–

D. C2O42–

E. HPO42–

15. Arrange the acids HOCl, HClO3, and HClO2 in order of increasing acid strength. A. HOCl < HClO3 < HClO2 B. HOCl < HClO2 < HClO3 C. HClO2 < HOCl < HClO3 D. HClO3 < HOCl < HClO2 E. HClO3 < HClO2 < HOCl

16. Arrange the acids HOBr, HBrO3, and HBrO2 in order of increasing acid strength. A. HOBr < HBrO3 < HBrO2 B. HOBr < HBrO2 < HBrO3 C. HBrO2 < HOBr < HBrO3 D. HBrO3 < HOBr < HBrO2 E. HBrO3 < HBrO2 < HOBr


17. Which one of these net ionic equations represents the reaction of a strong acid with a strong base? A.

H+(aq) + OH–(aq) H2O(aq)

B.

H+(aq) + CH3NH2(aq) CH3NH3+(aq)

C.

OH–(aq) + HCN(aq) H2O(aq) + CN–(aq)

D.

HCN(aq) + CH3NH2(aq) CH3NH3+(aq) + CN–(aq)

18. Which one of the following equations represents the ionization of a weak base in water? A. NH3(aq) + H2O(l) NH2

+(aq) + H3O+(aq) B. NH3(aq) + H2O(l) NH4

+(aq) + OH–(aq) C. NH3(aq) + H2O(l) NH4

– (aq) + OH+(aq) D. NH3(aq) + OH–(aq) NH2

– (aq) + H2O(l) E. NH3(aq) + H3O+(aq) NH4

+(aq) + H2O(l)

19. Predict the direction in which the equilibrium will lie for the reaction

H2CO3 + F– HCO3– + HF. Ka1( H2CO3) = 4.2 10–7; Ka(HF) = 7.1 10–4

A. to the right B. to the left C. in the middle

20. Which of the following is both a Lewis Acid and Brønsted Acid? A. BF3 B. NH3 C. CO2 D. HNO2 E. PCl3


21. The oxides CO2 and SO3 will form the following acids in water, respectively. A. H2CO3(aq) and H2SO3(aq) B. H2CO3(aq) and H2SO4(aq) C. H2CO2(aq) and H2SO3(aq) D. H2CO2(aq) and H2SO4(aq) E. HCOO-(aq) and H2SO3(aq)

22. Calculate the concentration of oxalate ion (C2O42–) in a 0.175 M solution of oxalic acid (C2H2O4).

[For oxalic acid, Ka1 = 6.5 10–2, Ka2 = 6.1 10–5.] A. 0.11 M

B. 6.1 10–5 M

C. 4.0 10–6 M D. 0.0791 M E. 0.175 M

23. For H3PO4, Ka1 = 7.3 10–3, Ka2 = 6.2 10–6, and Ka3 = 4.8 10–13. An aqueous solution of NaH2PO4 therefore would be A. neutral. B. basic. C. acidic.

24. For H3PO4, Ka1 = 7.3 10–3, Ka2 = 6.2 10–6, and Ka3 = 4.8 10–13. An aqueous solution of Na3PO4 therefore would be A. neutral. B. basic. C. acidic.

25. Which one of these salts will form a neutral solution on dissolving in water? A. NaCl B. KNO2 C. NaCN D. NH4NO3 E. FeCl3


26. Which one of these salts will form a basic solution on dissolving in water? A. NaCl B. KCN C. NaNO3 D. NH4NO3 E. FeCl3

27. The pH of a 0.14 M solution of an unknown monoprotic acid is 5.85. Calculate the Ka of the acid. A. 1.4 x 10-6 B. 1.4 x 10-11 C. 1.0 x 10-5 D. 7.1 x 10-9 E. 2.0 x 10-7

28. Calculate the pH of a 0.021 M NaCN solution. [Ka(HCN) = 4.9 10–10] A. 1.68 B. 3.18 C. 5.49 D. 7.00 E. 10.82

29. Calculate the pH of a 0.055 M solution of CH3COONa. (Ka(CH3COOH) = 1.8 x 10-5) A. 12.74 B. 4.74 C. 8.74 D. 9.26 E. 5.26

30. Calculate the pH of a 0.18 M solution of KNO2. (Ka (HNO2) = 4.5 x 10-4) A. 5.70 B. 8.30 C. 2.05 D. 11.95 E. 9.91


31. Which one of these salts will form a basic solution upon dissolving in water? A. NaCl B. NaNO2 C. NH4NO3 D. KBr E. AlCl3

32. Which one of the following salts will form an acidic solution on dissolving in water? A. LiBr B. NaF C. KOH D. FeCl3 E. NaCN

33. What mass of sodium nitrite must be added to 350. mL of water to give a solution with pH = 8.40?

[Ka(HNO2) = 5.6 10–4] A. 68 g

B. 1.7 10–4 g C. 0.039 g D. 8.3 g E. 24 g

34. What is the pH of a solution prepared by mixing 50.0 mL of 0.300 M HCl with 450.0 mL of 0.400

M HIO3? [Ka(HIO3) = 1.6 10–1] A. 1.52 B. 0.80 C. 0.72 D. 0.89 E. 0.66


35. Aspartic acid (C4H7NO4), one of the 20 essential amino acids, has two ionizable hydrogens. At

25C, Ka1 = 1.38 10–4 and Ka2 = 1.51 10–10. What is the concentration of doubly ionized aspartate ions in a 0.125 M aqueous solution of aspartic acid?

A. 3.33 10–2 M

B. 4.16 10–3 M

C. 4.15 10–3 M

D. 1.51 10–10 M

E. 2.08 10–14 M

36. Calculate the H+ ion concentration in a solution with a pH of 3.85.

A. 1.0 10–4 M

B. 1.4 10–4 M

C. 1.8 10–4 M

D. 2.2 10–4 M E. None of the above

37. If the pH of stomach acid is 1.0, what is the hydroxide ion concentration in this solution?

A. 4 10–13 M

B. 3 10–13 M

C. 2 10–13 M

D. 1 10–13 M E. None of the above

38. A 8.0 M solution of formic acid (HCOOH) is 0.47% ionized. What is the Ka of formic acid?

A. 1.57 10–4

B. 1.77 10–4

C. 1.97 10–4

D. 2.17 10–4 E. None of the above


39. Calculate the pH of a 0.011 M solution of NH4NO3. (Kb(NH3) = 1.8 x 10-5) A. 5.21 B. 5.41 C. 5.61 D. 5.81 E. None of the above

40. Calculate the pH of a 0.20 M solution of the weak base pyridine. (C5H5N; Kb = 1.7 x 10-9) A. 9.17 B. 9.27 C. 9.37 D. 9.47 E. None of the above


CHEM 1312. Chapter 15. Acids and Bases (Homework) S Key

1. D 2. E 3. C 4. B 5. B 6. C 7. B 8. E 9. B 10. B 11. C 12. B 13. B 14. B 15. B 16. B 17. A 18. B 19. B 20. D 21. B 22. B 23. C 24. B 25. A


26. B 27. B 28. E 29. C 30. B 31. B 32. D 33. D 34. D 35. D 36. B 37. D 38. B 39. C 40. B


CHEM 1312. Chapter 15. Acids and Bases (Homework) S Summary

Category # of Questions

Blooms Level: 3. Apply 4

Blooms Level: 4. Analyze 32

Blooms Level: 5. Evaluate 4

Chang - Chapter 15 40

Difficulty: Difficult 5

Difficulty: Easy 2

Difficulty: Medium 33

Gradable: automatic 40

Section: 15.01 3

Section: 15.02 1

Section: 15.03 5

Section: 15.04 6

Section: 15.05 6

Section: 15.06 2

Section: 15.08 4

Section: 15.09 2

Section: 15.10 9

Section: 15.11 1

Section: 15.12 1

Subtopic: Acid-Base definitions 5

Subtopic: Acid-Base Properties of Oxides and Hydroxides 1

Subtopic: Acid-Base Properties of Salts (Hydrated Metal Ions) 8

Subtopic: Acid-Base Strengths 4

Subtopic: Autoionization of water 1

Subtopic: Autoionization of water (Kw) 9

Subtopic: Lewis Acids and Bases 1

Subtopic: Molecular Structure and Acid Strength (Nonmetal hydrides, Oxoacids) 3

Subtopic: pH Scale 18

Subtopic: Polyprotic Acids 4

Subtopic: Weak Acid Equilibrium (Ka) 7

Subtopic: Weak Acid Equilibrium (Kb) 4

Topic: Acids and Bases 40

Documents

CHEM 1312. Chapter 15. Acids and Bases (Homework) S