$CrO_4^{2-}$ (yellow) changes to $Cr_2O_7^{2-}$ (orange) in $pH = x$ and vice-versa in $pH = y$. Hence,$x$ and $y$ are

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

The first and second ionization constants of a weak dibasic acid $H_{2}A$ are $8.1 \times 10^{-8}$ and $1.0 \times 10^{-13}$ respectively. $0.1 \text{ mol}$ of $H_{2}A$ was dissolved in $1 \text{ L}$ of $0.1 \text{ M}$ $HCl$ solution. The concentration of $HA^{-}$ in the resultant solution is:

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

Identify the correct statements from the following.
$(A)$ The ionic product of water at $100^{\circ} C$ is $< 10^{-14}$.
$(B)$ $pH$ of a solution decreases with increasing temperature.
$(C)$ $NaH_2PO_4$ on hydrolysis gives a basic solution.
$(D)$ $NH_3$ can act both as Bronsted acid and base.

Which of the following absorbs oxygen rapidly?