The change in enthalpy $[\Delta H]$ in $\mathrm{kJ} \mathrm{mol}^{-1}$ for the reaction, $\mathrm{Mg}+2 \mathrm{~F} \longrightarrow \mathrm{MgF}_2$ is

Given, electron affinity of $\mathrm{F}=328 \mathrm{~kJ} \mathrm{~mol}^{-1}$,

IE ${ }_1$ of $\mathrm{Mg}=737 \mathrm{kJmol}^{-1}, \mathrm{IE}_2$ of $\mathrm{Mg}=1451 \mathrm{kJmol}^{-1}$

A certain mass of a gas was brought from state $A$ to $B$ by following three different paths, namely 1,2 and 3 , respectively. Which of the following relations is correct for the work done?

Among the following given substances, the one with zero $\Delta_f H^{\circ}$ is

If 92 g Na reacts with water in open vessel at 300 K . What is the value of work done?

[Assume ideal nature of the gaseous product.]