What is the hydroxide ion concentration of a 2.56 x 10^-3 M HCl solution?

Answer 1

Recall the following:

[H⁺][OH^-] = Kw = 1x10^-14

HCl ==> H⁺ + Cl^-

2.56x10^-3 M HCl = 2.56x10^-3 M H⁺

pH = -log [H⁺] = -l0g 2.56x10^-3

[H⁺][OH^-] = 1x10^-14

[OH^-] = 1x10-¹⁴/2.56x10^-3

[OH^-] = 3.90x10^-12 M