If acetic acid is mixed with sodium acetate,then the ${H^{+}}$ ion concentration will be:

Statement $A$: Addition of $NH_4OH$ in the presence of excess $NH_4Cl$ to an aqueous solution of $BaCl_2$ results in the precipitation of $Ba(OH)_2$.
Reason $R$: $Ba(OH)_2$ is insoluble in water.

At $298 \ K$ the molar solubility of $Cd(OH)_2$ in $0.1 \ M \ KOH$ solution is $x \times 10^{-y}$. The values of $x$ and $y$ are respectively (at $298 \ K, \ K_{sp}$ of $Cd(OH)_2 = 2.5 \times 10^{-14}$)

Calculate the degree of ionization of $0.05 \ M$ acetic acid if its $p K_{ a }$ value is $4.74$. How is the degree of dissociation affected when its solution also contains $(a)$ $0.01 \ M$ $HCl$ and $(b)$ $0.1 \ M$ $HCl$?

When $NH_4Cl$ is added to $NH_4OH$ solution,the dissociation of $NH_4OH$ is reduced. This is due to:

Assertion : $Sb_2S_3$ is not soluble in yellow ammonium sulphide. Reason : The common ion effect due to $S^{2-}$ ions reduces the solubility of $Sb_2S_3$.