$A$ precipitate of calcium oxalate will not dissolve in

$A$ solution containing $0.01 \ M \ Zn^{2+}$ and $0.01 \ M \ Cu^{2+}$ is saturated with $H_2S$ gas. The concentration of $S^{2-}$ is $8.1 \times 10^{-21} \ M$. Given that the $K_{sp}$ values for $ZnS$ and $CuS$ are $3.0 \times 10^{-22}$ and $8.0 \times 10^{-36}$ respectively,which of the following will occur in the solution?

The solubility of $AgCl_{(s)}$ with solubility product $1.6 \times 10^{-10}$ in $0.1 \ M \ NaCl$ solution would be

The $K_{sp}$ of $M(OH)_2$ is $3.2 \times 10^{-11}$. The $pH$ of its saturated solution in water is:

If equal volumes of $AB_2$ and $XY$ (both are salts) aqueous solutions are mixed,which of the following combinations will give a precipitate of $AY_2$ at $300 \ K$? (Given $K_{sp}$ (at $300 \ K$) for $AY_2 = 5.2 \times 10^{-7}$)

The solubility product of a salt $AB$ is $1 \times 10^{-8}$ in a solution in which the concentration of $A$ is $10^{-3} \ M$. The salt will precipitate when the concentration of $B$ becomes more than: