Answer: A
2) The acid-dissociation constant at 25.0 °C for hypochlorous acid (HClO) is 3.0 108 . At equilibrium, the molarity of H 3 O in a 0.010 M solution of HClO is __________. A) 1.7 105 B) 0.010 C) 5.8 1010 D) 4.76 E) 2.00 3) Using the data in the table, which of the conjugate acids below is the weakest acid?
Answer: A
A) NH 4 B) C5 H5 NH C) H3 NOH
D) NH3CH3 E) NH 4 and NH3CH3
Answer: D
4) The K of hypochlorous acid (HClO) is 3.0 108 at 25.0 C . What is the % ionization of hypochlorous acid a in a 0.015M aqueous solution
of HClO at 25.0 C? A) 4.5 108 B) 14 C) 2.1105 D) 0.14 E) 1.4 103
Answer: D
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5) The hydride ion, H , is a stronger base than the hydroxide ion, OH . The product(s) of the reaction of hydride ion with water is/ are __________. A) H 3 O (aq) B) OH (aq) H 2 (g) C) OH (aq) 2H (aq) D) no reaction occurs E) H 2 O 2 (aq) 6) The molar concentration of hydroxide ion in pure water at 25 °C is __________. A) 1.00 B) 0.00 C) 1.0 1014 D) 1.0 107 E) 7.00 7) K a Answer: B
Answer: D
for HX is 7.5 1012 . What is the pH of a 0.15 M aqueous solution of NaX?
A) 7.97 B) 1.96 C) 6.00 D) 8.04 E) 12.10
Answer: E
8) The pH of a 0.15 M aqueous solution of NaZ (the sodium salt of HZ) is 10.7. What is the K A) 1.6 106 B) 6.0 109 C) 8.9 104 D) 1.3 1012 E) 3.3 108
a
for HZ?
Answer: B
9) The base-dissociation constant of ethylamine (C 2 H 5 NH 2 ) is 6.4 104 at 25.0 °C. The [H ] in a 1.6 102 M solution of ethylamine is __________ M. A) 3.5 1012 B) 2.9 103 C) 3.11012 D) 3.2 103 E) 11.46
2
Answer: A
10) The acid-dissociation constant of hydrocyanic acid (HCN) at 25.0 °C is 4.9 1010 . What is the pH of an aqueous solution of 0.080 M sodium cyanide (NaCN)? A) 11.11 B) 2.89 C) 1.3 103 D) 7.8 1012 E) 3.9 1011
Answer: A
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