$K_{sp} = [Mg^{+2}][OH^-]^2$
$1\times 10^{-12} = [0.01][OH^-]^2$
$[OH^-]^2=1\times 10^{-10} \,\,\, [OH^-] = 10^{-5}$
$\therefore \,\,\,\,[{H^ + }]\,\, = \,\,\frac{{{{10}^{_{ - 14}}}}}{{{{10}^{ - 5}}}} = \,\,{10^{ - 9}}$
$pH= - log[H^+] = -log [10^{-9}] = 9$
$(a)$ $ 10^{-10}$ $(b)$ $\frac{{Kw}}{{{{10}^{ - 10}}}}$ $(c)$ $\frac{{Kw}}{{{{10}^{ - 8}}}}$ $(d)$ $10^{-4}$
$0.1\, M$ ફોર્મિક એસિડ $(a)$
$0.1\, M$ એસિટિક એસિડ $(b)$
$0.1\, M$ બેન્ઝોઇક એસિડ $(c)$