pH of aqueous `K_(2)S` solution is

At what molar concentration of aqueous nitrouse acid ( K_a = 4.5x10^(-4)) the pH of the aqueous solution is 2.

The pH of an aqueous solution is Zero. The solution is

Approximate PH of 0.10 M aqueous H_2S solution having K_1 and K_2 for H_2S at 25^@C are 10^(-7) and 10^(-13) respectively is :