Assign $A, B, C, D$ from the given type of reaction.
$SrC_2O_4(s) + 2HCl(aq) \longrightarrow SrCl_2(aq) + H_2C_2O_4(aq)$

Arrange the following in increasing order of solubility product $(K_{sp})$: $Ca(OH)_2, AgBr, PbS, HgS$

Assertion : Addition of silver ions to a mixture of aqueous sodium chloride and sodium bromide solution will first precipitate $AgBr$ rather than $AgCl$.
Reason : $K_{sp}$ of $AgCl < K_{sp}$ of $AgBr$.

Solid $Ba(NO_3)_2$ is gradually dissolved in $1.0 \times 10^{-4} \, M \, Na_2CO_3$ solution. At which concentration of $Ba^{2+}$ will the precipitation begin? $(K_{sp} \, BaCO_3 = 5.1 \times 10^{-9})$

The solubility product of silver bromide is $5.0 \times 10^{-13}$. The quantity of potassium bromide (molar mass taken as $120 \ g \ mol^{-1}$) to be added to $1 \ L$ of $0.05 \ M$ solution of silver nitrate to start the precipitation of $AgBr$ is

Find out the solubility of $Ni(OH)_2$ in $0.1 \ M \ NaOH$.
Given that the solubility product constant $(K_{sp})$ of $Ni(OH)_2$ is $2 \times 10^{-15}$.