Which of the following oxidation reactions are carried out by both $\mathrm{K}_2 \mathrm{Cr}_2 \mathrm{O}_7$ and $\mathrm{KMnO}_4$ in acidic medium?

A. $\Gamma^{-} \rightarrow \mathrm{I}_2$

B. $\mathrm{S}^{2-} \rightarrow \mathrm{S}$

C. $\mathrm{Fe}^{2+} \rightarrow \mathrm{Fe}^{3+}$

D. $\mathrm{I}^{-} \rightarrow \mathrm{IO}_3^{-}$

E. $\mathrm{S}_2 \mathrm{O}_3{ }^{2-} \rightarrow \mathrm{SO}_4^{2-}$

Choose the correct answer from the options given below :

The molecules having square pyramidal geometry are

Ice and water are placed in a closed container at a pressure of 1 atm and temperature 273.15 K . If pressure of the system is increased 2 times, keeping temperature constant, then identify correct observation from following

The formation enthalpies, $\Delta \mathrm{H}_{\mathrm{f}}^{\ominus}$ for $\mathrm{H}_{(\mathrm{g})}$ and $\mathrm{O}_{(\mathrm{g})}$ are 220.0 and $250.0 \mathrm{~kJ} \mathrm{~mol}^{-1}$, respectively, at 298.15 K , and $\Delta \mathrm{H}_{\mathrm{f}}^{\ominus}$ for $\mathrm{H}_2 \mathrm{O}_{(\mathrm{g})}$ is $-242.0 \mathrm{~kJ} \mathrm{~mol}^{-1}$ at the same temperature. The average bond enthalpy of the $\mathrm{O}-\mathrm{H}$ bond in water at 298.15 K is _______ $\mathrm{kJ} \mathrm{~mol}^{-1}$ (nearest integer).