(a) If the solubility of $\mathrm{Ag}_{2} \mathrm{Cr}_{2} \mathrm{O}_{4}$ is $6.5 \times 10^{-5} \mathrm{mol} \mathrm{dm}^{-3},$ determine the solubility
product for this salt.
(b) $K_{\mathrm{sp}}$ for $\mathrm{AgCl}$ is $1.8 \times 10^{-10} .$ Why can silver chromate (which is red) be used to indicate the end point in titrations involving the precipitation of $\mathrm{AgCl} ?$