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Which of the following mixtures would not be suitable for preparing a buffer solution?


A) NH4Cl and NH3
B) HNO3 and NaNO3
C) HF and KF
D) C6H5COOH (Benzoic acid) and C6H5COO - Na+
E) CH3COOH and CH3COO - Na+

F) A) and C)
G) A) and E)

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Consider the two buffer solutions prepared below: Solution A: [HA] = 0.15 M and [A - ] = 0.25 M Solution B: [HA] = 1.50 M and [A - ] = 2.50 M Which statement below is true regarding the pH and buffering capacity of these two solutions?


A) Solution A will have a greater pH value and a smaller buffering capacity.
B) Solution B will have a greater pH value and a smaller buffering capacity.
C) Solution B will have a greater pH value and a larger buffering capacity.
D) The pH of both solutions will be identical but Solution A will have a larger buffering capacity.
E) The pH of both solutions will be identical but Solution B will have a larger buffering capacity.

F) A) and E)
G) C) and D)

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Carbonic acid is a diprotic acid with K al = 4.3×10 - 7 and K a2 = 5.6×10 - 11. Estimate the pH of a solution of sodium hydrogen carbonate.


A) pH = 2
B) pH = 4
C) pH = 6
D) pH = 8
E) pH = 10

F) A) and B)
G) C) and D)

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Which of the following salts, each having very limited solubility in water, would dissolve to a greater extent upon acidifying the solution? I. Ag2S II. Mg3(PO4) 2 III. AgBr


A) I only
B) II only
C) I and II
D) All of these
E) None of these

F) A) and E)
G) A) and B)

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Which of the following titrations would produce a pH equal to 7.0 at the equivalence point? I. Titrating NH3 with standard HCl (delivered from the burette) II. Titrating HCl with standard NaOH (delivered from the burette) III. Titrating CH3COOH with standard NaOH (delivered from the burette)


A) I only
B) II only
C) III only
D) II and III
E) All of these

F) B) and C)
G) A) and D)

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Which of the following general combinations of substances form an acid-base buffer when added to water?


A) a strong acid and the sodium salt of its conjugate base
B) a strong base and the chloride salt of its conjugate acid
C) a weak acid and the sodium salt of its conjugate base
D) a weak acid
E) a weak base and a strong base

F) C) and D)
G) B) and D)

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Calculate the pH of a buffer prepared by dissolving 0.10 mol of NH4Cl in 1.00 L of 0.15 M NH3. K b = 1.8×10 - 5 for NH3.


A) 9.43
B) 4.56
C) 11.34
D) 2.72
E) 4.74

F) All of the above
G) A) and D)

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What is the volume of 0.0175 M Ba(OH) 2 required to neutralize 10.0 mL of 0.0300 M HCl?


A) 10.0 mL
B) 34.2 mL
C) 17.1 mL
D) 8.6 mL
E) 4.3 mL

F) D) and E)
G) B) and E)

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A sample of 0.100 mole of acetic acid ( K a = 1.8×10 - 5) in 50.0 mL of solution is titrated with standard 0.100 M NaOH. What is the pH in the titration flask after addition of 25.0 mL of the base?


A) 2.88
B) 3.18
C) 2.60
D) 4.74
E) 11.40

F) B) and E)
G) C) and D)

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Calculate the pH of a solution formed when 1.5 L oF4.5×10 - 3 M HCl is mixed witH₂ .0 L of 3.0×10 - 3 M HNO3.


A) 3.67
B) 3.74
C) 2.25
D) 3.16
E) 2.44

F) A) and E)
G) None of the above

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Exhibit 16-1 Consider the equilibrium reaction below to answer the following question(s) . HNO₂ + H₂ O Exhibit 16-1 Consider the equilibrium reaction below to answer the following question(s) . HNO₂ + H₂ O   H₃O + + NO₂ 1 - K a (HNO₂ )  = 4.5 10 - 4 -Refer to Exhibit 16-1. What is the concentration of nitrite ion, NO₂ - , present at equilibrium if 0.100 moles of HCl are added to 0.200 moles of HNO₂ to form one-liter of solution? A)  [NO<sub>2</sub><sup> - </sup>] = 9.00×10<sup> - 4</sup> M B)  [NO<sub>2</sub><sup> - </sup>] = 2.12×10<sup> - 3</sup> M C)  [NO<sub>2</sub><sup> - </sup>] = 9.49×10<sup> - 3</sup> M D)  [NO<sub>2</sub><sup> - </sup>] = 0.100 M E)  [NO<sub>2</sub><sup> - </sup>] = 0.200 M H₃O + + NO₂ 1 - K a (HNO₂ ) = 4.5 10 - 4 -Refer to Exhibit 16-1. What is the concentration of nitrite ion, NO₂ - , present at equilibrium if 0.100 moles of HCl are added to 0.200 moles of HNO₂ to form one-liter of solution?


A) [NO2 - ] = 9.00×10 - 4 M
B) [NO2 - ] = 2.12×10 - 3 M
C) [NO2 - ] = 9.49×10 - 3 M
D) [NO2 - ] = 0.100 M
E) [NO2 - ] = 0.200 M

F) A) and E)
G) A) and B)

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Oxalic acid is diprotic with p K al = 1.23 and p K a2 = 4.19. What is p K b for the hydrogen oxalate ion?


A) 1.23
B) 4.19
C) 7.00
D) 9.81
E) 12.77

F) D) and E)
G) C) and D)

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A sample of acetic acid (approximately 0.001 M, K a = 1.8×10 - 5) is titrated with 0.00993 M NaOH. What indicator should be used?


A) thymol blue (p K In = 1.65)
B) methyl orange (p K In = 3.46)
C) methyl red (p K In = 5.00)
D) bromthymol blue (p K In = 7.30)
E) phenolphthalein (p K In = 8.7)

F) A) and B)
G) A) and C)

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A 0.10 M solution of hydrazine (N2H4, K b = 1.7×10 - 6) containing an unknown concentration of hydrazine hydrochloride (N2H5Cl) has a pH of 7.50. What is the concentration of N2H5Cl in the solution?


A) 1.26 M
B) 0.54 M
C) 5.8 M
D) 0.10 M
E) 0.72 M

F) A) and C)
G) A) and B)

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A buffer was prepared such that the pH was 5.20. If the solution contains 0.400 moles of acetic acid (CH3COOH) per liter, what is the concentration of the acetate ion (CH3COO - ) in this solution? The p K a for acetic acid is 4.74.


A) 0.40 M
B) 0.14 M
C) 4.2×10 - 3 M
D) 6.3×10 - 6 M
E) 1.1 M

F) B) and E)
G) A) and B)

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In the titration of 25.0 mL of a solution of a weak acid HX with 0.250 M NaOH, the pH = 4.50 after the addition of 5.0 mL of the NaOH solution. The equivalence point occurs when 30.4 mL of the NaOH solution has been added. What is the ionization constant ( K a) of HX?


A) 1.4×10 - 5
B) 3.2×10 - 5
C) 6.2×10 - 6
D) 3.2×10 - 10
E) 7.2×10 - 10

F) B) and E)
G) A) and B)

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Consider the titration of a weak acid with a strong base . Which statement below is true regarding the equivalence point in this titration?


A) It occurs at a pH = 7.0 because the acid has been neutralized.
B) It occurs at a pH less than 7.0 because an acidic salt is formed.
C) It occurs at a pH less than 7.0 because a basic salt is formed.
D) It occurs at a pH greater than 7.0 because an acidic salt is formed.
E) It occurs at a pH greater than 7.0 because a basic salt is formed.

F) A) and B)
G) D) and E)

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Solutions are made by combining equal amounts of the following. Which is a buffer?


A) 0.1 M HCl + 0.1 M Cl -
B) 0.1 M HF + 0.1 M Na+
C) 0.1 M HF + 0.1 M NaOH
D) 0.1 M NaF + 0.05 M HF
E) 0.1 M NaF + 0.05 M Na+

F) A) and C)
G) A) and B)

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Consider a buffer solution containing a weak acid, HX, and a salt of the weak acid's conjugate base, NaX. Under what conditions is the pH greater than the p K a of the weak acid?


A) When the p K a equals 7.0.
B) When [HX] > [NaX].
C) When [HX] < [NaX].
D) When [HX] = [NaX].
E) When there is no NaX present.

F) A) and E)
G) B) and D)

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What volume of 0.200 M H₂ SO₄is required to neutralize 50.0 mL of 0.100 M NaOH? Assume the chemical equation is: H₂ SO₄(aq) + 2 NaOH (aq) Na2 SO₄(aq) + 2 H₂ O ( What volume of 0.200 M H₂ SO₄is required to neutralize 50.0 mL of 0.100 M NaOH? Assume the chemical equation is: H₂ SO₄(aq)  + 2 NaOH (aq)  Na<sub>2</sub> SO₄(aq)  + 2 H₂ O (   )  A)  50.0 mL B)  25.0 mL C)  100 mL D)  12.5 mL E)  6.25 mL )


A) 50.0 mL
B) 25.0 mL
C) 100 mL
D) 12.5 mL
E) 6.25 mL

F) C) and E)
G) None of the above

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