18. Aqueous Equilibrium

A benzoate buffer is prepared containing 0.33 M benzoic acid and 0.28 M benzoate. The Ka of benzoic acid is 6.3 x 10^-5. What is the pH of the buffer after the addition of 20 mL of 0.50 M NaOH to 100 mL of this buffer?

A buffer contains equal amounts of a weak acid and its conjugate base and has a pH of 5.25. How will the concentration of the weak acid in the buffer change after the addition of a small amount of strong base?

A buffer contains the weak acid HA and its conjugate base A⁻. The weak acid has a pKa of 5.25 and the buffer has a pH of 4.82. Which statement is true of the relative concentrations of the weak acid and the conjugate base in the buffer?

A buffer solution is made by dissolving 0.780 moles of NaClO in 1.00 L of 0.560 M HClO. What is the pH of the solution after 0.140 moles of NaOH is added? The Ka of HClO is 2.9 × 10^-8.

Calculate the pH value for a buffer solution prepared by adding 1.0 mL of a 0.10M acetic acid solution to 20 mL of a 0.10M sodium acetate solution. (Ka = 1.7 × 10⁻⁵)

If you have 500.0 mL of a 0.10 M solution of HClO, what mass of NaClO (molar mass = 74.44 g/mol) do you need to add to make a buffer with a pH of 7.5?

Suppose you are performing an experiment that requires a constant pH of 4.75. Which of the following buffer systems would be most appropriate based on the given Ka values?

Which component of the acetic acid buffer pair would react with added HCl?

Which component of the acetic acid buffer pair would react with added NaOH?

Which of the following represents the complete ionic equation for the reaction that occurs when a few drops of nitric acid (HNO3) are added to a buffer solution containing acetic acid (CH3COOH) and sodium acetate (CH3COONa)?