Question
Calculate the electron gain enthalpy of fluorine from the data given below: $\Delta_{\mathrm{f}} \mathrm{H}^{\circ}$ of $\mathrm{KF}=-560.8 \mathrm{~kJ} \mathrm{~mol}{ }^{-1}$, Sublimation energy of $\mathrm{K}=87.8 \mathrm{~kJ} \mathrm{~mol}^{-1}$, Dissociation energy of F , is $158.9 \mathrm{~kJ} \mathrm{~mol}{ }^{-1}$, Lattice energy of $\mathrm{KF}^{-15}-807.5 \mathrm{~kJ} \mathrm{~mol}{ }^{-1}$ and Ionisation energy of K is $414.2 \mathrm{~kJ} \mathrm{~mol}^{-1}$.