A solution is 0.0100 ,M in and 0.0100 ,M in

CHEMISTRY · Subjective · AP · Chemistry · Equilibrium · Equilibrium

Problem

A solution is 0.0100\,M in

\mathrm{Fe^{3+}}

and 0.0100\,M in

\mathrm{Cr^{3+}}

. The solubility products at 25 °C are

K_{\text{sp}}\,(\mathrm{Fe(OH)_3})=2.8\times10^{-39}

and

K_{\text{sp}}\,(\mathrm{Cr(OH)_3})=6.7\times10^{-31}

. Calculate the pH range over which

\mathrm{Fe(OH)_3}

precipitates while

\mathrm{Cr(OH)_3}

remains completely in solution, and state which hydroxide forms first as the pH is increased.