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

The first ionization constant of $H_2S$ is $9.1 \times 10^{-8}$. Calculate the concentration of $HS^{-}$ ion in its $0.1 \ M$ solution. How will this concentration be affected if the solution is $0.1 \ M$ in $HCl$ also? If the second dissociation constant of $H_2S$ is $1.2 \times 10^{-13}$,calculate the concentration of $S^{2-}$ under both conditions.

When dilute $H_2SO_4$ is added to an aqueous solution of potassium chromate,the yellow color of the solution changes to orange. This indicates that .....

The initial rate of hydrolysis of methyl acetate $(1 \ M)$ by a weak acid $(HA, 1 \ M)$ is $1/100$th of that of a strong acid $(HX, 1 \ M)$ at $25^{\circ} C$. The $K_a$ of $HA$ is:

At $STP$,the dissociation reaction of water is $H_2O \rightleftharpoons H^{+}(aq.) + OH^{-}(aq.)$,and the $pH$ of water is $7.0$. The change of standard free energy $(\Delta G^{\circ})$ for the above dissociation process is given by

The increasing order of $pH$ of $0.1 \ M$ solution of the following compounds is: