Acids Quiz #5 pH calculations for Strong and Weak Acids Answers

1. The 1.0 M acidic solution with the highest pH is

A. H₂S

B HNO₂

C. HNO₃

D. H₃BO₃

2. At 25 ^oC, the equation representing the ionization of water is

A H₂O + H₂O ⇄ 2H₂ + O₂

B. H₂O + H₂O ⇄ H₂O₂ + H₂

C. H₂O + H₂O ⇄ 4H⁺ + 2O^2-

D. H₂O + H₂O ⇄ H₃O⁺ +OH^-

3. The pH of a 0.3 M solution of NH₃ is approximately

A. 14.0

B. 11.0

C. 6.0

D. 3.0

4. The pH of an aqueous solution is 4.32. The [OH^-] is

A. 6.4 x 10^-1 M

B. 4.8 x 10^-5 M

C. 2.1 x 10^-10 M

D. 1.6 x 10^-14 M

5. The pH of an aqueous solution is 10.32. The [OH^-] is

A. 5.0 x 10^-12 M

B. 2.0 x 10^-11 M

C. 4.8 x 10^-11 M

D. 2.1 x 10^-4 M

6. The pH of a 0.025 M HClO₄ solution is

A. 0.94

B. 1.60

C. 12.40

D. 13.06

7. Consider the following equilibrium

H₂O_(l) ⇄ H₂O_(l) ⇄ H₃O⁺_(aq) + OH^-_(aq)

The equilibrium constant for this system is referred to as

A. K_w

B. K_a

C. K_b

D. K_sp

8. The [H₃O^-] in a solution of pH 0.60 is

A. 4.0 x 10^-14 M

B. 2.2 x 10^-1 M

C. 2.5 x 10^-1 M

D. 6.0 x 10^-1 M

9. A solution is prepared by adding 100 mL of 10 M of HCl to a 1 litre volumetric

flask and filling it to the mark with water. The pH of this solution is

A. -1

B. 0

C. 1

D. 7

10. The approximate pH of a 0.06 M solution of CH₃COOH is

A. 1

B. 3

C. 11

D. 13

11. The [OH^-] is greater than the [H₃O⁺] in

A. HCl_(aq)

B. NH_3(aq)

C. H₂O_(aq)

D. CH₃COOH_(aq)

12. The pH of 0.15 M HCl is

A. 0.15

B. 0.71

C. 0.82

D. 13.18

13. Which of the following equations correctly relates pH and [H₃O⁺] ?

A. pH= log [H₃O⁺]

B. pH= 14 - [H₃O⁺]

C. pH= -log [H₃O⁺]

D. pH= pK_w – [H₃O⁺]

14. The pH of 0.20 M HNO₃ is

A. 0.20

B. 0.63

C. 0.70

D. 1.58

15. The [OH^-] in 0.050 M HNO₃ at 25^oC is

A. 5.0 x 10^-16 M

B. 1.0 x 10^-14 M

C. 2.0 x 10^-13 M

D. 5.0 x 10^-2 M

16. What is the approximate pH of a 1.0 M solution of the salt NH₄Cl?

A. 0.0

B. 5.0

C. 7.0

D. 10.0

17. What is the approximate pH of a 1.0 M solution of the salt NH₃?

A. 2.0

B. 5.0

C. 7.0

D. 10.0

18. What is the approximate pH of a 1.0 M solution of the salt NaHCO₃?

A. 2.0

B. 5.0

C. 7.0

D. 9.0

19. What is the approximate pH of a 1.0 M solution of the salt AlCl₃?

A. 0.0

B. 3.0

C. 7.0

D. 9.0

20. What is the approximate pH of a 1.0 M solution of the salt NaHSO₄?

A. 0.0

B. 3.0

C. 7.0

D. 9.0

21. Which of the following is a definition of pH?

A. pH = +Log[H₃O⁺]

B. pH = -Log[OH^-]

C. pH = -Log[H₃O⁺]

D. pH = pOH + pKw

22. What is the mass of NaOH required to prepare 100.0 mL of NaOH_(aq) that has a

pH = 13.62 ?

A. 0.38 g

B. 0.42 g

C. 1.67 g

D. 0.14 g

23. What is the [KOH] in a KOH solution that has a pH =12.00?

A.        0.010 M

B. 0.56 M

C. 2.0 M

D. 2.0 x 10^-12 M

24. What is the [H₃O⁺] in 0.70 M HCN ?

A. 0.70 M

B. 1.9 x 10^-5 M

C. 1.0 x 10^-6 M

D. 2.4 x 10^-10 M

25. What is the value of pKw for water at 25 ⁰C ?

A. 10 x 10^-14

B. 10 x 10^-7

C. 7.00

D. 14.00

26. What pH would most likely result when CO₂ dissolves naturally in rainwater?

A. 3.5

B. 6.5

C. 7.2

D. 7.8

27. What is the pOH of 0.05 M Ba(OH)₂ ?

A. 1.0

B. 1.3

C. 12.7

D. 13.0

28. What is the pH of 0.5 M Sr(OH)₂ ?

A. 0.0

B. 0.3

C. 12.7

D. 14.0

29. Which of the following statements is true for an acidic solution at 25 ⁰C ?

A. pH > 7.0

B. pOH < 7.0

C. [H₃O⁺] < [OH^-]

D. [H₃O⁺] > [OH^-]

30. What is the [OH^-] in 0.025 M HCl ?

A. 2.5 x 10^-16 M

B. 4.0 x 10^-13 M

C. 2.5 x 10^-2 M

D. 1.6 M