Solid $Ba(NO_3)_2$ is gradually dissolved in a $1.0 \times 10^{-3} \,M \,Na_2CO_3$ solution. At what concentration of $Ba^{2+}$ will be precipitate begin to form ($K_{sp}$ for $BaCO_3 = 5.1 \times 10^{-9}$)

At $298\, K$ , the solubility product of $PbC{l_2}$ is $1.0 \times {10^{ – 6}}$. What will be the solubility of $PbC{l_2}$ in moles/litre

The concentration of $500$ $ML$ $NaOH$ solution is $0.02$ $M$. How many grams of $FeS{O_4}$ added in this solution for precipitation of $Fe{\left( {OH} \right)_2}$ ? The ${K_{sp}}$ of $Fe{\left( {OH} \right)_2}$ is $1.5 \times {10^{ – 15}}$. Molecular mass of $Fe{\left( {OH} \right)_2}$ is $ 152$ $g$ $mol^{-1}$ )

The values of ${K_{sp}}$for $CuS,\,\,A{g_2}S$ and $HgS$ are ${10^{ – 31}},\,{10^{42}}$ and ${10^{ – 54}}$ respectively. The correct order of their solubility in water is

Solubility of $M{X_2}$ type electrolyte is $0.5 \times {10^{ – 4}}\,mole/litre$. The value of ${K_{sp}}$ of the electrolyte is