1) What mass of KHCO3 must be added to 500. mL of a 0.200 M H2CO3 solution to prepare a buffer with pH = 6.30?
(a) 8.73 g
(b) 4.55 g
(c) 24.07 g
(d) 8.33 g
2) What mass of NH4Cl must be added to 500. mL of a 0.150 M NH3 solution to prepare a buffer with pH = 9.50?
(a) 1.14 g
(b) 2.54 g
(c) 6.97 g
(d) 2.31 g
3) What mass of NH4Cl must be added to 200. mL of a 0.200 M NH3 solution to prepare a buffer with pH = 9.30?
(a) 1.95 g
(b) 1.12 g
(c) 2.34 g
(d) 1.11 g
4) What mass of sodium acetate must be added to 1.00 L of a 0.200 M acetic acid solution to prepare a buffer with pH = 4.50?
(a) 28.5 g
(b) 5.99 g
(c) 9.44 g
(d) 7.63 g
5) What volume of a 4.00 M ammonium chloride solution must be added to 250. mL of a 0.250 M ammonia solution to prepare a buffer with pH = 9.10?
(a) 22.58 mL
(b) 6.39 mL
(c) 10.81 mL
(d) 7.44 mL
6) What volume of a 4.50 M sodium acetate must be added to 250. mL of a 0.200 M acetic acid solution to prepare a buffer with pH = 5.00?
(a) 20.22 mL
(b) 7.17 mL
(c) 23.02 mL
(d) 6.11 mL
7) What volume of a 5.00 M sodium acetate must be added to 1.00 L of a 0.200 M acetic acid solution to prepare a buffer with pH = 4.50?
(a) 69.51 mL
(b) 14.61 mL
(c) 23.02 mL
(d) 17.63 mL
8) What volume of a 2.50 M HCO3- solution must be added to 500. mL of a 0.150 M CO32- solution to prepare a buffer with pH = 10.00?
(a) 9.71 mL
(b) 62.68 mL
(c) 14.36 mL
(d) 7.44 mL
9) What volume of a 4.50 M sodium nitrite must be added to 250. mL of a 0.200 M nitrous acid solution to prepare a buffer with pH = 3.00?
(a) 24.87 mL
(b) 4.96 mL
(c) 6.77 mL
(d) 3.43 mL
10) What volume of a 3.00 M HCO3- solution must be added to 200. mL of a 0.200 M CO32- solution to prepare a buffer with pH = 10.30?
(a) 12.73 mL
(b) 6.51 mL
(c) 14.36 mL
(d) 13.96 mL
11) What volume of a 3.50 M KHCO3 must be added to 500. mL of a 0.200 M carbonic acid solution to prepare a buffer with pH = 6.30?
(a) 13.55 mL
(b) 12.97 mL
(c) 34.35 mL
(d) 23.76 mL
12) What mass of NaHCO3 must be added to 250. mL of a 0.250 M CO32- solution to prepare a buffer with pH = 10.50?
(a) 1.14 g
(b) 3.16 g
(c) 7.95 g
(d) 3.47 g
13) What mass of sodium acetate must be added to 250. mL of a 0.200 M acetic acid solution to prepare a buffer with pH = 5.00?
(a) 7.46 g
(b) 2.65 g
(c) 12.44 g
(d) 9.01 g
14) What mass of sodium nitrite must be added to 250. mL of a 0.200 M nitrous acid solution to prepare a buffer with pH = 3.00?
(a) 30.90 g
(b) 1.54 g
(c) 3.44 g
(d) 1.07 g