Chapt. 15 Practice Test

AP Chemistry

Chapt. 15 Practice Test

1. What is the formula for the hydronium ion?

2. In the reaction H2CO3 + H2O HCO3 + H3O+, the Brønsted acids are ______and ______

3. Identify the conjugate base of HPO42 in the following reaction:

HCO3 + HPO42 H2CO3 + PO43

4. Identify the conjugate acid of SO42 in the following reaction:

CO32 + HSO4 HCO3 + SO42

5. Which one of the following 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.

6. One liter of an aqueous solution contains 6.02  1021 H3O+ ions. Therefore its H3O+ ion concentration is

A.0.0100 mole per liter.

B.0.100 mole per liter.

C.1.00 mole per liter.

D.6.02  1021 mole per liter.

E.6.02  1023 mole per liter.

7. What is the concentration of H+ in a 2.5 M HCl solution?

8. The OH concentration in a 1.0  103 M Ba(OH)2 solution is ______

9. What is the H+ ion concentration in a 4.8  102 M KOH solution?

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

A.0.84 M

B.0.12 M

C.0.10 M

D.0.084 M

E.8.4  103 M

11. Consider the weak acid CH3COOH (acetic acid). If a 0.048 M CH3COOHsolution is 5.2% ionized, determine the [H3O+] concentration at equilibrium.

A. 0.25 M B. 9.2  103 M C. 0.048 M D. 0.052 M E. 2.5  103 M

12. Calculate the pH of a juice in which the hydrogen ion concentration is 6.3  105 M.

13. Calculate the pH of a 6.71  102 M NaOH solution.

14. What is the pH of a 0.014 M Ca(OH)2 solution?

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

16. The pH of a Ba(OH)2 solution is 10.00. What is the H+ ion concentration of this solution?

17. 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?

18. The pOH of a solution is 9.60 Calculate the hydrogen ion concentration in this solution.

19. Which solution will have the lowest pH?

A.0.10 M HCN B. 0.10 M HNO3 C. 0.10 M NaCl D. 0.10 M H2CO3 E.0.10 M NaOH

20. Which one of the following responses is true with regard to a 0.1 M solution of a weak acid HA?

A.[H+] > [A]B. pH = 1.0C. [H+] < [A]D. pH > 1.0E.[OH] > [H+]

21. Acid strength decreases in the series HI > HSO4 > HF > HCN. Which of the following anions is the weakest base?

A.IB. SO42C. FD. CN

22. Which acid listed below is the strongest?

A.H2SeO3 B. H2TeO3C. H2SO3

23. Arrange the acids HOCl, HClO3, and HClO2 in order of increasing acid strength.

24. When comparing acid strength of binary acids HX, as X varies within a particular group of the periodic table, which one of the following factors dominates in affecting the acid strength?

A.bond strength

B.electron withdrawing effects

C.percent ionic character of the H–X bond

D.solubility

E.Le Châtelier's principle

25. Which one of the following net ionic equations represents the reaction of a strong acid with a weak 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)

26. Which one of the following equations represents the reaction of a weak 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)

27. Predict the direction in which the equilibrium will lie for the following reaction:

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

28. Predict the direction in which the equilibrium will lie for the following reaction:

H2SO3(aq) + HCO3(aq) HSO3(aq) + H2CO3(aq)

Ka1(H2SO3) = 1  102; Ka1(H2CO3) = 4.2  107

29. Which of the following yields a basic solution when dissolved in water?

A. NO2 B. P4O10 C. K2O D. NaCl E. SO2

30. P4O10 is classified as an acidic oxide because it

A.reacts with acids to produce a salt.

B.is insoluble in water.

C.reacts with water to produce OH.

D.gives a solution of phosphoric acid, H3PO4, on dissolving in water.

E.can act as a Lewis base by donating electron pairs.

31. In the reaction CaO(s) + SO2(g) CaSO3(s),

A.O2 acts as a Lewis base, and SO2 acts as a Lewis acid.

B.Ca2+ acts as a Lewis base, and SO42 acts as a Lewis acid.

C.SO42 acts as a Lewis base, and SO2 acts as a Lewis acid.

D.SO2 acts as a Lewis base, and O2 acts as a Lewis acid.

E.SO2 acts as a Lewis base, and Ca2+ acts as a Lewis acid.

32. Which of the following will act as a Lewis acid?

A. NH3 B. NH4+ C. H2O D. BF3 E. F

33. 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.]

34. 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

35. An aqueous solution of KCl would be

A. neutral B. basic C. acidic

36. What is the pH of a 0.20 M solution of NH4Cl? [Kb(NH3) = 1.8  105]

37. Which response gives the products of hydrolysis of NH4Cl?

A.NH4+ + HCl

B.NH3 + OH + HCl

C.NH3 + H+

D.NH4OH + HCl

E.No hydrolysis occurs.

38. 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

39. 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 gB. 1.7  104 gC. 0.039 g D. 8.3 g E. 24 g