5 Steps to a 5 AP Chemistry 2019

Take a Diagnostic Exam ‹ 25

67. Assuming all concentrations are 1 M, which of the
    following is the most acidic solution (lowest pH)?
    (A) KBr (potassium bromide) and HBr (hydro-
    bromic acid)
    (B) H 2 C 2 O 4 (oxalic acid) and KHC 2 O 4 (potas-
    sium hydrogen oxalate)
    (C) NH 3 (ammonia) and NH 4 NO 3 (ammonium
    nitrate)
    (D) (CH 3 ) 2 NH (dimethylamine) and HC 2 H 3 O 2
    (acetic acid)


68. Assuming all concentrations are equal, which of
    the following solutions has pH nearest 7?
    (A) KBr (potassium bromide) and HBr (hydro-
    bromic acid)
    (B) H 2 C 2 O 4 (oxalic acid) and KHC 2 O 4 (potas-
    sium hydrogen oxalate)
    (C) NH 3 (ammonia) and NH 4 NO 3 (ammonium
    nitrate)
    (D) (CH 3 ) 2 NH (dimethylamine) and HC 2 H 3 O 2
    (acetic acid)


69. Which of the following yields a buffer with a
    pH > 7 upon mixing equal volumes of 1 M
    solutions?
    (A) KBr (potassium bromide) and HBr (hydro-
    bromic acid)
    (B) H 2 C 2 O 4 (oxalic acid) and KHC 2 O 4 (potas-
    sium hydrogen oxalate)
    (C) NH 3 (ammonia) and NH 4 NO 3 (ammonium
    nitrate)
    (D) (CH 3 ) 2 NH (dimethylamine) and HC 2 H 3 O 2
    (acetic acid)


70. Which of the following will give a buffer with a
    pH < 7 when equal volumes of 1 M solutions of
    each of the components are mixed?
    (A) KBr (potassium bromide) and HBr (hydro-
    bromic acid)
    (B) H 2 C 2 O 4 (oxalic acid) and KHC 2 O 4 (potas-
    sium hydrogen oxalate)
    (C) NH 3 (ammonia) and NH 4 NO 3 (ammonium
    nitrate)
    (D) (CH 3 ) 2 NH (dimethylamine) and HC 2 H 3 O 2
    (acetic acid)
    71. Determine the OH-(aq) concentration in 0.0010 M
    pyridine (C 5 H 5 N) solution. (The Kb for pyridine is
    9 × 10 -^9 .)
    (A) 5 × 10 -^1 M
    (B) 1 × 10 -^3 M
    (C) 3 × 10 -^6 M
    (D) 9 × 10 -^9 M
    72. SnS(s)++2H++(aq)Sn^2 (aq) HS 2 (aq)
    The successive acid dissociation constants for
    H 2 S are 9.5 × 10 -^8 (Ka1) and 1 × 10 -^19 (Ka2).
    The Ksp, the solubility product constant, for SnS
    equals 1.0 × 10 -^25. What is the equilibrium con-
    stant for the above reaction?
    (A) 9.5 × 10 -^8 /1.0 × 10 -^25
    (B) 9.5 × 10 -^27 /1.0 × 10 -^25
    (C) 1.0 × 10 -^25 /9.5 × 10 -^27
    (D) 1 × 10 -^19 /1.0 × 10 -^25
    73. NO 24 (g)2 NO 2 (g) endothermic
    An equilibrium mixture of the compounds is
    placed in a sealed container at 150°C. Which of
    the following changes may increase the amount
    of the product?
    (A) raising the temperature of the container
    (B) increasing the volume of the container and
    raising the temperature of the container
    (C) adding 1 mole of Ar(g) to the container
    (D) adding 1 mole of Ar(g) to the container and
    raising the temperature of the container
    74. The Ksp for LaF 3 is 2 × 10 -^9. What is the molar
    solubility of this compound in water?
    (A) 210/27× −^9

(B)^4210 × −^19

(C)^2210 × −^19

(D)^4 210/27× −^9

75. The Ksp for Mn(OH) 2 is 1.6 × 10 -^13. What is the
    molar solubility of this compound in water?
    (A)^3 4.0× 10 −^14
    (B) 1.6 × 10 -^13
    (C)^3 4.0× 10 −^13

(D)^2 4.0× 10 −^14