What is the $pH$ of a solution saturated with aluminum hydroxide?

Comment on your answer.

b$)$ Will the solubility of $Al(OH)$ be greater or smaller :

in a $0\mathrm{.}1M$ solution of $Al(NO3)3?$

in a $0\mathrm{.}1$MKNO$3$ solution?

c$)$ Express the solubility of aluminum hydroxide as a function of $pH,$ also considering the following complexation equilibrium

$Al3++4OH-=AL(OH)$

$Kc={10}^{{?}^{{?}^{?}}}33\mathrm{.}4$

d$)$ Using the relationship found in the previous point, determine the $pH$ values for precipitation and redissolution of

aluminum hydroxide, assuming that the concentration of the free or complexed ion is at most ${10}^{{?}^{{?}^{?}}}-5M.$