$25.0 \ mL$ of $0.050 \ M \ Ba(NO_3)_2$ is mixed with $25.0 \ mL$ of $0.020 \ M \ NaF$. The $K_{sp}$ of $BaF_2$ is $0.5 \times 10^{-6}$ at $298 \ K$. The ratio of $[Ba^{2+}][F^{-}]^2$ to $K_{sp}$ is $.......$. (Nearest integer)

How many grams of $CaC_2O_4$ will dissolve in distilled water to make $1 \, L$ of a saturated solution (in $, g$)? The solubility product $(K_{sp})$ of $CaC_2O_4$ is $2.5 \times 10^{-9} \, mol^2 \, L^{-2}$ and its molar mass is $128 \, g \, mol^{-1}$.

What is the minimum concentration of $SO_4^{2-}$ required to precipitate $BaSO_4$ in a solution containing $1.0 \times 10^{-4} \ M \ Ba^{2+}$ ($K_{sp}$ for $BaSO_4$ is $4 \times 10^{-10}$)?

The values of $K_{sp}$ of two sparingly soluble salts $Ni(OH)_2$ and $AgCN$ are $2.0 \times 10^{-15}$ and $6 \times 10^{-17}$ respectively. Which salt is more soluble? Explain.

If the solubility of salts $M_2X$,$QY_2$,and $PZ_3$ is the same $(S < 1)$,what is the relationship between their solubility products $(K_{sp})$?

The $K_{sp}$ for bismuth sulphide $(Bi_{2}S_{3})$ is $1.08 \times 10^{-73}$. The solubility of $Bi_{2}S_{3}$ in $mol \ L^{-1}$ at $298 \ K$ is ......