Answer Options:
5.3 × 10^2
5.3 × 10^3
5.3 × 10^4
5.3 × 10^5
Answer: 5.3 × 10^-5
Question: A 750.9 mL solution of a buffer made with nitrous acid, HNO_2, begins at 0.877 M pH 3.19. Calculate the change in pH when 29.2 mL of 0.225 M HNO_3 is added.
Answer Options:
+0.07
-0.73
+0.30
-1.61
+0.06
-0.29
Answer: +0.06
Question: What is the pH of a 0.25 M nicotine, C_10H_14N_2, solution?
Answer Options:
3.98
11.01
10.70
9.29
6.40
13.40
2.24
11.76
Answer: 10.70
Question: A reaction is sensitive to pH and must be kept at or near pH 10.65. Which base would be best for creating a buffer for the reaction?
Answer Options:
Base 2 (K_b = 3.7 x 10^-9)
Base 5 (K_b = 4.7 x 10^-9)
Base 1 (K_b = 1.8 x 10^-9)
Base 4 (K_b = 4.5 x 10^-9)
Answer: Base 2 (K_b = 3.7 x 10^-9)
Question: Will the pH of a 0.788 M LiC_5H_5O (lithium benzoate) solution be acidic, basic, or neutral at 25°C? (Hint: Look at the tables for K_a and K_b. This compound has an ion similar, but not identical to, benzoic acid)
Answer Options:
acidic
basic
neutral
Answer: basic
Question: What is the % ionization of a 0.38 M acetic acid, HC_2H_3O_2, solution? The pH of the solution is 2.58.
Answer Options:
0.69%
0.26%
6.86%
14.1%
15.3%
Answer: 1.32%
Question: What is the concentration of H_2S in a 0.690 M NaHS solution at equilibrium? H_2S(aq). (Hint: Use the K_a values for H_2S given in the table.)
Answer Options:
7.87 x 10^-8 M
2.37 x 10^-8 M
4.21 x 10^-7 M
1.80 x 10^-7 M
8.83 x 10^-8 M
2.01 x 10^-8 M
Answer: 4.21 x 10^-7 M
Question: Calculate the expected pH for a 1.7 x 10^-7 M solution of NaOH at 25°C.
Answer Options:
6.67
7.23
6.81
7.33
7.70
6.77
Answer: 7.33
Question: What is the pH of a 6.69 x 10^-9 M nitrous acid, HNO_2, solution?
Answer Options:
2.17
11.19
2.81
1.83
11.39
2.76
2.71
11.24
Answer: 2.81
Question: Determine the pH of a 0.775 M diprotic acid, H_2AsO_4^-, solution. K_a1 = 8.0 x 10^-3 K_a2 = 1.3 x 10^-7
Answer Options:
5.75
6.89
2.60
2.89
8.19
6.11
Answer: 2.60
Question: What is the pH of a 0.210 M C_5H_5NHCl solution? (Hint: Look at the tables for K_a and K_b. This compound has an ion similar, but not identical to pyridine)
Answer Options:
2.96
6.68
1.32
5.16
1.69
12.44
11.04
12.31
Answer: 5.16
Question: What is the pH of a solution made by mixing 245 mL of 0.595 M HC_2H_3O_2 (acetic acid) and 433 mL of 0.574 M KC_2H_3O_2 (of HC_2H_3O_2, Ka = 3.3 x 10^-5)?
Answer Options:
3.37
3.52
4.87
3.68
2.09
5.34
Answer: 4.87
Question: Which combination will result in a buffered solution? [select all that apply]
Answer Options:
300 mL 0.1 M CH_3NH_2 and 800 mL 0.1 M CH_3NH_3^+Cl^-
300 mL 0.1 M CH_3NH_2 and 300 mL 0.1 M HCl
500 mL 0.1 M CH_3NH_2 and 500 mL 0.1 M HCl
300 mL 0.1 M CH_3NH_2 and 100 mL 0.1 M HCl
800 mL 0.1 M CH_3NH_2 and 500 mL 0.1 M HCl
Answer: 300 mL 0.1 M CH_3NH_2 and 800 mL 0.1 M CH_3NH_3^+Cl^-