student copy hw 15a

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CHE 134 – HW 15A Name:)________________________________________________________________ _______________ 1. What is the formula for the hydronium and the hydroxide ions? 2. In the reaction H 2 CO 3 + H 2 O → HCO 3 + H 3 O + , the Brønsted acids are? 3. Identify the conjugate pairs of each reaction. a) HCO 3 + HPO 4 2– → H 2 CO 3 + PO 4 3– b) H 2 PO 4 + HSO 4 → H 3 PO 4 + SO 4 2– c) CO 3 2– + HSO 4 → HCO 3 + SO 4 2– d) CO 3 2– + HSO 4 → HCO 3 + SO 4 2– e) CO 3 2– + H 2 PO 4 → HCO 3 + HPO 4 2– 4. What is the pH of an aqueous solution that contains 2.7 10 20 H 3 O + ions per liter of solution? 5. The OH concentration in a 1.0 10 –3 M Ba(OH) 2 solution is

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Page 1: Student Copy HW 15A

CHE 134 – HW 15A

Name:)_______________________________________________________________________________

1. What is the formula for the hydronium and the hydroxide ions?

2. In the reaction H2CO3 + H2O → HCO3– + H3O+, the Brønsted acids are?

3. Identify the conjugate pairs of each reaction.

a) HCO3– + HPO4

2– → H2CO3 + PO43–

b) H2PO4– + HSO4

– → H3PO4 + SO42–

c) CO32– + HSO4

– → HCO3– + SO4

2–

d) CO32– + HSO4

– → HCO3– + SO4

2–

e) CO32– + H2PO4

– → HCO3– + HPO4

2–

4. What is the pH of an aqueous solution that contains 2.7 1020 H3O+ ions per liter of solution?

5. The OH– concentration in a 1.0 10–3 M Ba(OH)2 solution is

6. What is the H+ ion concentration in a 4.8 10–2 M KOH solution?

Page 2: Student Copy HW 15A

CHE 134 – HW 15A

7. Calculate the H+ ion concentration in a 8.8 10–4 M Ca(OH)2 solution.

8. A 0.10 M HF solution is 8.4% ionized. Calculate the H+ ion concentration.

9. Consider the weak acid CH3COOH (acetic acid). If a 0.048 M CH3COOH solution is 5.2% ionized, determine the [H3O+] concentration at equilibrium.

10. Calculate the pH of a carbonated beverage in which the hydrogen ion concentration is 3.4 10–4 M.

11. Determine the pH of a KOH solution made by mixing 0.251 g KOH with enough water to make 1.00 102 mL of solution.

12. Calculate the pH of a 0.10 M HCN solution that is 0.0070% ionized.

13. Calculate the pH of 2.6 10–2 M KOH.

14. Calculate the hydrogen ion concentration in a solution of fruit juice having a pH of 4.25.

Page 3: Student Copy HW 15A

CHE 134 – HW 15A

15. Calculate the hydrogen ion concentration in a solution having a pH of 4.60.

16. Diet cola drinks have a pH of about 3.0, while milk has a pH of about 7.0. How many times greater is the H3O+ concentration in diet cola than in milk?

17. The pH of coffee is approximately 5.0. How many times greater is the [H+] in coffee than in neutral water?

18. Acid strength decreases in the series HI > HSO4– > HF > HCN. Which of these anions is the

weakest base?

19. Arrange the acids HBr, H2Se, and H3As in order of increasing acid strength.

20. 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)

21. 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

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

C6H5COO– + HF → C6H5COOH + F– Ka[C6H5COOH] = 6.5 10–5; Ka[HF] = 7.1 10–4