Keq - Types of Equilibrium Constants - Hydrolysis Constants

Hydrolysis Constants

In aqueous solution the concentration of the hydroxide ion is related to the concentration of the hydrogen ion by

The first step in metal ion hydrolysis can be expressed in two different ways

It follows that β* = K K_W. Hydrolysis constants are usually reported in the β* form and this leads to them appearing to have strange values. For example, if lg K = 4 and lg K_W = −14, lg β* = 4 + (−14) = −10. In general when the hydrolysis product contains n hydroxide groups lg β* = lg K + n lg K_W