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Chem 116 - General Chemistry II

Buffer Solutions

Effects of Adding the Salt of the Conjugate Base

An aqueous solution of HN3 (KA=1.9×10-5) is at equilibrium. If solid KN3 is slowly added to this solution, how does this alter the pH, concentration of hydroxide, concentration of HN3 and percent ionization of HN3?

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Which one of the Following Constitutes a Buffer Solution

Which one of the following constitutes a buffer solution after equal volumes of both solutions are mixed?

0.1 M HBr and 0.2 M NaBr
0.1 M NH3 and 0.2 M NaOH
0.1 M H2SO3 and 0.2 M NaHSO3
0.2 M H2SO3 and 0.1 M NaOH
0.2 M H2SO3 and 0.1 M HBr

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pH of a Buffer Solution

A solution is 0.40 M in NaHC2O4 and 0.25 M in Na2C2O4. What is the pH of this solution? (for H2C2O4: KA1 = 5.6×10-2 and KA2 = 5.4×10-5)

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Acid/Base Ratio to Prepare a Solution of Specified pH

For an experiment, the (CH3)2NH (KB = 5.9×10-4)/(CH3)2NH2Cl system has been chosen to give a buffer solution with a pH of 11.00. What concentration ratio of base to acid should be used?

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pH Following Acid Addition to a Buffer Solution

A buffer solution is 1.00 M in HC2H3O2 (KA = 1.8×10-5) and 0.20 M in NaC2H3O2. What is the pH of this solution after the addition of 0.10 mol HCl to 750. mL of this buffer solution?

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Calculating pH

Calculate the pH of a solution consisting of 0.50 M CH3COOH and 0.50 M CH3COONa.

Note: Ka of CH3COOH = 1.8 X 10-5

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Adding a Strong Base to a Buffer

Calculate the pH of a solution resulting when 0.020 mol of NaOH (s) is added to 1.0 L of a buffer consisting of 0.50 M CH3COOH and 0.50 M CH3COONa.

Assume the addition causes a negligible change in volume.

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Adding a Strong Acid to a Buffer

Calculate the pH of a solution resulting when 0.020 mol of HCl (g) is added to 1.0 L of a buffer consisting of 0.50 M CH3COOH and 0.50 M CH3COONa.

Assume the addition causes a negligible change in volume.

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Adding a Strong Acid to a Buffer

A buffer consists of 3.0 M NH3 (Kb = 1.8 X 10-5) and 2.0 M NH4Cl. What is the pH of this buffer after the addition of 1.5 moles of HNO3 to 1.0 L of this buffer? (Assume the volume does not change on the addition of the HNO3).

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