Assign $A, B, C, D$ from the given type of reaction.
$BaCO_3 \downarrow + CO_2 + H_2O \longrightarrow Ba(HCO_3)_2$

If $pK_{a} = -\log K_{a} = 4$ for a weak acid $HX$ and $K_{a} = C\alpha^{2}$,then the Van't Hoff factor when $C = 0.01 \ M$ is

What is the degree of dissociation of $CH_3COOH$ if $\wedge^{\circ}(CH_3COO^{-}) = 50 \ S \ cm^2 \ mol^{-1}$,$\wedge^{\circ}(H^{+}) = 350 \ S \ cm^2 \ mol^{-1}$ and the molar conductivity of $5 \times 10^{-2} \ M \ CH_3COOH$ is $20 \ S \ cm^2 \ mol^{-1}$?

The $pH$ of the solution containing $10 \ mL$ of $0.1 \ N$ $NaOH$ and $10 \ mL$ of $0.05 \ N$ $H_2SO_4$ would be

The pairs of compounds which cannot exist together in aqueous solution are :
$I. NaH_2PO_4$ and $Na_2CO_3$ $II. Na_2CO_3$ and $NaHCO_3$
$III. NaOH$ and $NaH_2PO_4$ $IV. NaHCO_3$ and $NaOH$

$A$ solution of $0.1 \ M$ weak base $(B)$ is titrated with $0.1 \ M$ of a strong acid $(HA)$. The variation of $pH$ of the solution with the volume of $HA$ added is shown in the figure below. What is the $pK_{b}$ of the base? The neutralization reaction is given by $B + HA \rightarrow BH^{+} + A^{-}$.