Which of the following would increase the solubility of $Pb(OH)_2$?

The $K_{sp}$ of $AgBr$ at $25 \, ^\circ C$ is $4.9 \times 10^{-13}$. If the molar mass of $AgBr$ is $188 \, g/mol$,how much $AgBr$ is required to saturate $20 \, L$ of water?

Given that the solubility product constants $(K_{sp})$ follow the order $K_{sp}(Mg(OH)_2) > K_{sp}(Zn(OH)_2) > K_{sp}(Fe(OH)_3)$,what is the order of precipitation of these hydroxides?

At $298 \ K$,the solubility of silver chloride in water is $1.434 \times 10^{-3} \ g \ L^{-1}$. The value of $-\log K_{sp}$ for silver chloride is $........$ (Given: molar mass of $Ag = 107.9 \ g \ mol^{-1}$ and $Cl = 35.5 \ g \ mol^{-1}$)

Why is only $As^{3+}$ precipitated as $As_2S_3$ when $H_2S$ is passed through an acidic solution containing $As^{3+}$ and $Zn^{2+}$,while $Zn^{2+}$ is not precipitated as $ZnS$?

The solubility of $AgCN$ in a buffer solution of $pH = 3$ is $x$. The value of $x$ is [Assume : No cyano complex is formed; $K_{sp}(AgCN) = 2.2 \times 10^{-16}$ and $K_{a}(HCN) = 6.2 \times 10^{-10}$]