The pH of a 01 M MCl M is an unknown metal cation was found

The pH of a 0.1 M MCl ( M is an unknown metal cation) was found to be 2.8. Write the net ionic equation for the hydrolysis of the metal cation and solve it\'s corresponding equilibrium constant, Kb.

Solution

Solution:-

From the pH, we can determine the [H^+]

10^-pH = 10^-2.8 = 1.58*10^-3 M [ same is the [Cl^-]

Ka = [(1.58*10^-3) (1.58*10^-3)] / 0.1

Ka = 0.0000249

Kb = Kw/Ka = 1.00 x 10^-14 / 0.0000249 = 4.02 x 10^-10