$5\%$ ionization occurs in $0.01 \ M$ $CH_3COOH$ solution. Calculate its dissociation constant.

Equal volumes of three acid solutions with $pH$ values of $3, 4,$ and $5$ are mixed. What will be the concentration of $H^+$ ions in the resulting mixture?

If $20 \, mL$ of $0.25 \, N$ strong acid and $30 \, mL$ of $0.2 \, N$ strong base are mixed,then the resulting solution is

For the reaction in aqueous solution $Zn^{2+} + X^{-} \rightleftharpoons ZnX^{+}$,the $K_{eq}$ is greatest when $X$ is

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 $NaOH$

Which of the following statements regarding $pH$ and $[H^+]$ is incorrect?