At $298 \ K$,the solubility of $PbCl_2$ is $2 \times 10^{-2} \ mol/L$. Calculate the $K_{sp}$.

At $20 \, ^\circ C$,the $Ag^+$ ion concentration in a saturated solution of $Ag_2CrO_4$ is $1.5 \times 10^{-4} \, mol/L$. At $20 \, ^\circ C$,the solubility product of $Ag_2CrO_4$ would be:

The moles of $Ag^{+}$ which must be added to decrease the concentration of $Cl^{-}$ from $4 \times 10^{-5} \ M$ to $10^{-5} \ M$ in $100 \ mL$ solution,if $K_{sp}$ for $AgCl$ is $10^{-10} \ M^2$ at $25 \ ^oC$.

In an aqueous solution,$SCN^-$,$Br^-$,$I^-$,and $Cl^-$ are present. Which will get precipitated first when $AgNO_3$ is added to the solution? Given that:
$K_{sp}(AgCl) = 1.2 \times 10^{-10}$,
$K_{sp}(AgI) = 1.7 \times 10^{-16}$,
$K_{sp}(AgSCN) = 7.1 \times 10^{-7}$,
$K_{sp}(AgBr) = 3.5 \times 10^{-13}$

The solubility of $PbCl_2$ is equal to .......

How many grams of $CaC_2O_4$ (molecular mass $= 128$) on dissolving in one litre distilled water will give a saturated solution (in $g$)? $[K_{sp}(CaC_2O_4) = 2.5 \times 10^{-9} \ mol^2 \ L^{-2}]$