Which one of the following sulphides is only completely precipitated when the acidic solution is made dilute?

The solubility product of the sparingly soluble salt $AB_2$ is $2.56 \times 10^{-10}$ at $298 \ K$. Calculate its solubility in $mol \ dm^{-3}$ at the same temperature?

The molar solubility $(s)$ of zirconium phosphate with molecular formula $(Zr^{4+})_3(PO_4^{3-})_4$ is given by the relation:

The solubility of $CuBr$ is $2 \times 10^{-4} \ mol/L$ at $25 \ ^\circ C$. The $K_{sp}$ value for $CuBr$ is

$AgCl$ is soluble in:

$H_{2}S$ is passed into $1 \ L$ of a solution containing $0.1 \ mole$ of $Zn^{2+}$ and $0.01 \ mole$ of $Cu^{2+}$ until the sulphide ion concentration reaches $8.1 \times 10^{-19} \ M$. Which one of the following statements is true? $[K_{sp}$ of $ZnS$ and $CuS$ are $3 \times 10^{-22}$ and $8 \times 10^{-36}$ respectively.$]$