Question 1

What is the pH of a buffer solution that is composed of a weak acid, HA (K_a=4.2410⁹), and the conjugate base, A, after 0.94 mL of 0.082 M HCl solution is added. The initial concentrations of the 114 mL buffer solution are [HA]=0.74 M and [A]=0.6 M. Enter your value to two (2) decimal places.

Question 2

A solution containing 150 mL of 0.15 M weak acid (K_a = 1.9 10^-8) is titrated with 0.2 M NaOH solution. What is the pH of the solution after the addition of 138 mL of NaOH? - report you answer out to two decimal places - do not include units

Question 3

A 100.0 mL sample of 0.150 M hydrofluoric acid is titrated with a 0.250 M solution of sodium hydroxide. What is the pH of the solution after 30.0 mL of sodium hydroxide solution has been added?

- The K_a of hydrofluoric acid is 3.5 x 10⁴ - The pK_a of hydrofluoric acid is 3.46 - report answer in four significant figures