One mole of an ideal gas is expanded isothermally and reversibly to half of its initial pressure. $\Delta S$ for the process in $J \ K^{-1} \ mol^{-1}$ is $[\ln \ 2 = 0.693$ and $R = 8.314 \ J \ mol^{-1} \ K^{-1}]$

If the enthalpy of vaporization for water is $186.5 \ kJ \ mol^{-1}$,the entropy of its vaporization will be ...... $J \ K^{-1} \ mol^{-1}$ (Assume the boiling point of water is $373 \ K$).

Fill in the blanks:
$(i)$ The entropy of one mole of a substance at a fixed temperature and standard state is called ........ .
$(ii)$ The unit of molar entropy is .......... .
$(iii)$ The process of conversion of graphite into diamond is of ........ type.

What is the change in entropy of the surroundings for the reaction, $H_2(g) + 1/2 O_2(g) \rightarrow H_2O(l)$ at $298 \text{ K}$, if the standard enthalpy of formation of water is $-286 \text{ kJ mol}^{-1}$?

$30.4 \, kJ$ of heat is required to melt one mole of sodium chloride and the entropy change at the melting point is $28.4 \, J \, K^{-1} \, mol^{-1}$ at $1 \, atm$. The melting point of sodium chloride is $........... \, K$ (Nearest Integer).

In which of the following reactions is $\Delta S$ maximum?