Ha is a weak acid its ionization constant ka is 40 x 10-13

Question

HA is a weak acid. Its ionization constant, K_a, is 4.0 x 10^-13. Calculate the pH of an aqueous solution with an initial NaA concentration of 0.080 M.

We place 0.123 mol of a weak acid, HA, in enough water to produce 1.00 L of solution. The final pH of the solution is 1.27. Calculate the ionization contant, K_a, of HA.

We place 0.647 mol of a weak acid, HA, and 11.0 g of NaOH in enough water to produce 1.00 L of solution. The final pH of this solution is 4.56. Calculate the ionization constant, K_a, of HA.