Chapter15 1. Which is not a characteristic property of acids? A.tastes sour B.turns litmus from blue to red C.reacts with metals to yield CO 2 gas D.neutralizes bases E.reacts with carbonates to yield CO 2 gas 2. In the reaction H 2 CO 3 + H 2 O HCO 3 + H3 O +, the Brønsted acids are A.H 2 CO 3 and H 2 O. B.HCO 3 and H2 CO 3. C.H 2 O and H 3 O +. D.H 3 O + and H 2 CO 3. E.H 2 O and HCO 3. 3. In the reaction HSO 4 (aq) + OH (aq) SO4 2 (aq) + H2 O(l), the conjugate acidbase pairs are A.Row 1 B.Row 2 C.Row 3 D.Row 4 E.Row 5 4. Identify the conjugate base of HCO 3 in the reaction 2 CO 3 + HSO4 HCO 3 + 2 SO4 A.HSO 4 B.CO 3 2 C.OH D.H 3 O + E.SO 4 2 1
2 5. Identify the conjugate acid of SO 4 in the reaction 2 CO 3 + HSO4 HCO 3 + 2 SO4 A.CO 3 2 B.HSO 4 C.OH D.H 3 O + E.SO 4 2 6. Identify the conjugate acid of HCO 3 in the reaction HCO 3 + 2 3 HPO4 H 2 CO 3 + PO 4 A.H 2 O B.HCO 3 C.H 2 CO 3 D.PO 4 3 E.HPO 4 2 7. 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. 8. One liter of an aqueous solution contains 6.02 10 21 H 3 O + ions. Therefore, its H 3 O + ion concentration is A.0.0100 mole per liter. B.0.100 mole per liter. C.1.00 mole per liter. D.6.02 10 21 mole per liter. E.6.02 10 23 mole per liter. 2
9. What is the concentration of H + in a 2.5 M HCl solution? A.0 B.1.3 M C.2.5 M D.5.0 M E.10.M 10. The OH concentration in a 1.0 10 3 M Ba(OH) 2 solution is A.0.50 10 3 M. B.1.0 10 3 M. C.2.0 10 3 M. D.1.0 10 2 M. E.0.020 M. 11. What is the H + ion concentration in a 4.8 10 2 M KOH solution? A.4.8 10 2 M B.1.0 10 7 M C.4.8 10 11 M D.4.8 10 12 M E.2.1 10 13 M 12. 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 13. A 0.10 M NH 3 solution is 1.3% ionized. Calculate the H + ion concentration. NH 3 + H 2 O NH 4 + + OH A.1.3 10 3 M B.7.7 10 2 M C.7.7 10 12 M D.0.13 M E.0.10 M 3
14. Determine the ph of a KOH solution made by mixing 0.251 g KOH with enough water to make 1.00 10 2 ml of solution. A.1.35 B.2.35 C.7.00 D.11.65 E.12.65 15. Calculate the H + ion concentration in lemon juice having a ph of 2.4. A.4.0 10 2 M B.250 M C.0.38 M D.4.0 10 3 M E.12 M 16. Calculate the ph of a 3.5 10 3 M HNO 3 solution. A.2.46 B.0.54 C.2.46 D.3.00 E.3.46 17. Calculate the ph of a 0.14 M HNO 2 solution that is 5.7% ionized. A.0.85 B.1.70 C.2.10 D.11.90 E.13.10 18. Calculate the ph of a 6.71 10 2 M NaOH solution. A.12.83 B.2.17 C.11.82 D.6.71 E.1.17 4
19. What is the ph of a 0.014 M Ca(OH) 2 solution? A.1.85 B.1.55 C.12.15 D.12.45 E.15.85 20. Calculate the hydrogen ion concentration in a solution of fruit juice having a ph of 4.25. A.1.0 10 14 M B.5.6 10 5 M C.4.0 10 25 M D.2.5 10 4 M E.5.6 10 4 M 21. 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 H 3 O + concentration in diet cola than in milk? A.2.3 times higher in diet cola than in milk B.400 times higher in diet cola than in milk C.0.43 times higher in diet cola than in milk D.1,000 times higher in diet cola than in milk E.10,000 times higher in diet cola than in milk 22. What is the ph of a solution prepared by mixing 10.0 ml of a strong acid solution with ph = 2.00 and 10.0 ml of a strong acid solution with ph = 6.00? A.2.0 B.2.3 C.4.0 D.6.0 E.8.0 23. The poh of a solution is 9.60 Calculate the hydrogen ion concentration in this solution. A.2.5 10 10 M B.6.0 10 9 M C.4.0 10 5 M D.2.4 10 4 M E.1.0 10 14 M 5
24. Which solution will have the lowest ph? A.0.10 M HCN B.0.10 M HNO 3 C.0.10 M NaCl D.0.10 M H 2 CO 3 E.0.10 M NaOH 25. Which one of these responses is true with regard to a 0.1 M solution of a weak acid HA? A.[H + ] > [A ] B.pH = 1.0 C.[H + ] < [A ] D.pH > 1.0 E.[OH ] > [H + ] 26. Acid strength decreases in the series HI > HSO 4 > HF > HCN. Which of these anions is the weakest base? A.I B.SO 4 2 C.F D.CN 27. Acid strength increases in the series: HCN < HF < HSO 4. Which of these species is the strongest base? A.H 2 SO 4 B.SO 4 2 C.F D.CN E.HSO 4 28. Which of these acids is the strongest? A.H 2 SeO 3 B.H 2 TeO 3 C.H 2 SO 3 6
29. Arrange the acids HOCl, HClO 3, and HClO 2 in order of increasing acid strength. A.HOCl < HClO 3 < HClO 2 B.HOCl < HClO 2 < HClO 3 C.HClO 2 < HOCl < HClO 3 D.HClO 3 < HOCl < HClO 2 E.HClO 3 < HClO 2 < HOCl 30. Arrange the acids HOBr, HBrO 3, and HBrO 2 in order of increasing acid strength. A.HOBr < HBrO 3 < HBrO 2 B.HOBr < HBrO 2 < HBrO 3 C.HBrO 2 < HOBr < HBrO 3 D.HBrO 3 < HOBr < HBrO 2 E.HBrO 3 < HBrO 2 < HOBr 31. Arrange the acids HBr, H 2 Se, and H 3 As in order of increasing acid strength. A.HBr < H 2 Se < H 3 As B.HBr < H 3 As < H 2 Se C.H 2 Se < H 3 As < HBr D.H 3 As< H 2 Se < HBr E.H 3 As< HBr < H 2 Se 32. When comparing acid strength of binary acids HX, as X varies within a particular group of the periodic table, which one of these factors dominates in affecting the acid strength? A.bond strength B.electron withdrawing effects C.percent ionic character of the HX bond D.solubility E.Le Châtelier's principle 33. Which one of these equations represents the reaction of a weak acid with a weak base? A.H + (aq) + OH (aq) H 2 O(aq) B.H + (aq) + CH 3 NH 2 (aq) CH 3 NH 3 + (aq) C.OH (aq) + HCN(aq) H 2 O(aq) + CN (aq) D.HCN(aq) + CH 3 NH 2 (aq) CH 3 NH 3 + (aq) + CN (aq) 7
34. Predict the direction in which the equilibrium will lie for the reaction C 6 H 5 COO + HF C 6 H 5 COOH + F. K a (C 6 H 5 COOH) = 6.5 10 5 ; K a (HF) = 7.1 10 4 A.to the right B.to the left C.in the middle 35. Predict the direction in which the equilibrium will lie for the reaction H 3 PO 4 + NO 3 H 2 PO 4 + HNO3. K a (H 3 PO 4 ) = 7.5 10 3 A.to the right B.to the left C.in the middle 36. Which of the following yields a basic solution when dissolved in water? A.NO 2 B.P 4 O 10 C.K 2 O D.NaCl E.SO 2 37. Which of the following yields an acidic solution when dissolved in water? A.NO 2 B.LiOH C.K 2 O D.NaCl E.Ca(OH) 2 38. Which of these species will act as a Lewis acid? A.NH 3 B.NH 4 + C.H 2 O D.BF 3 E.F 8
39. Which of these species is a Lewis acid, but not a Brønsted acid? A.HCN B.CO 3 2 C.OH D.Cl E.Al 3+ 40. Which one of the following is a buffer solution? A.0.40 M HCN and 0.10 KCN B.0.20 M CH 3 COOH C.1.0 M HNO 3 and 1.0 M NaNO 3 D.0.10 M KCN E.0.50 M HCl and 0.10 NaCl 41. Which one of the following combinations cannot function as a buffer solution? A.HCN and KCN B.NH 3 and (NH 4 ) 2 SO 4 C.HNO 3 and NaNO 3 D.HF and NaF E.HNO 2 and NaNO 2 42. Calculate the ph of a buffer solution that contains 0.25 M benzoic acid (C 6 H 5 CO 2 H) and 0.15 M sodium benzoate (C 6 H 5 COONa). [K a = 6.5 10 5 for benzoic acid] A.3.97 B.4.83 C.4.19 D.3.40 E.4.41 43. You are asked to go into the lab and prepare an acetic acid sodium acetate buffer solution with a ph of 4.00 ± 0.02. What molar ratio of CH 3 COOH to CH 3 COONa should be used? A.0.18 B.0.84 C.1.19 D.5.50 E.0.10 9
44. What is the net ionic equation for the reaction that occurs when small amounts of hydrochloric acid are added to a HOCl/NaOCl buffer solution? A.H + + H 2 O H 3 O + B.H + + OCl HOCl C.HOCl H + + OCl D.H + + HOCl H 2 OCl + E.HCl + HOCl H 2 O + Cl 2 45. Assuming equal concentrations of conjugate base and acid, which one of the following mixtures is suitable for making a buffer solution with an optimum ph of 9.29.3? A.CH 3 COONa/CH 3 COOH (K a = 1.8 10 5 ) B.NH 3 /NH 4 Cl (K a = 5.6 10 10 ) C.NaOCl/HOCl (K a = 3.2 10 8 ) D.NaNO 2 /HNO 2 (K a = 4.5 10 4 ) E.NaCl/HCl 46. You have 500.0 ml of a buffer solution containing 0.20 M acetic acid (CH 3 COOH) and 0.30 M sodium acetate (CH 3 COONa). What will the ph of this solution be after the addition of 20.0 ml of 1.00 M NaOH solution? [K a = 1.8 10 5 ] A.4.41 B.4.74 C.4.56 D.4.92 E.5.07 47. In which one of the following solutions will acetic acid have the greatest percent ionization? A.0.1 M CH 3 COOH B.0.1 M CH 3 COOH dissolved in 0.1 M HCl C.0.1 M CH 3 COOH dissolved in 0.2 M HCl D.0.1 M CH 3 COOH plus 0.1 M CH 3 COONa E.0.1 M CH 3 COOH plus 0.2 M CH 3 COONa 10
Chapter15 Key 1.C 2.D 3.A 4.B 5.B 6.C 7.B 8.A 9.C 10.C 11.E 12.E 13.C 14.E 15.D 16.C 17.C 18.A 19.D 20.B 21.E 22.B 23.C 24.B 1
25.D 26.A 27.D 28.C 29.B 30.B 31.D 32.A 33.D 34.A 35.B 36.C 37.A 38.D 39.E 40.A 41.C 42.A 43.D 44.B 45.B 46.E 47.A 2