Aqueous solution of ${\mathrm{H}}_2\mathrm{S}$ contains ${\mathrm{H}}_2\mathrm{S}, {\mathrm{HS}}^{-},{\mathrm{S}}^{-2},{\mathrm{H}}_3{\mathrm{O}}^{+},{\mathrm{OH}}^{-} \mathrm{and} {\mathrm{H}}_2\mathrm{O}$ in varying concentrations.Which of these species can act only as a base ? Which can act only as acid ? Which can act both an acid and as a base?

Write an expression for $\mathrm{Kp}$for the above reaction.

Dihydrogen gas is obtained from natural gas by partial oxidation with steam as per following endothermic reaction:

${\mathrm{CH}}_4\left(\mathrm{g}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{g}\right)\rightleftharpoons \mathrm{CO}\left(\mathrm{g}\right)+3{\mathrm{H}}_2\left(\mathrm{g}\right)$

How will the values of ${\mathrm{K}}_{\mathrm{p}}$ and composition of equilibrium mixture be affected by increasing the pressure.