If lattice enthalpy and hydration enthalpy of $$\mathrm{KCl}$$ are $$699 \mathrm{~kJ} \mathrm{~mol}^{-1}$$ and $$-681.8 \mathrm{~kJ} \mathrm{~mol}^{-1}$$ respectively. What is the enthalpy of solution of $$\mathrm{KCl}$$ ?

For reaction, $$\mathrm{CO}_{(\mathrm{g})}+\frac{1}{2} \mathrm{O}_{2(\mathrm{~g})} \longrightarrow \mathrm{CO}_{2(\mathrm{~g})}$$

Which of the following equations is CORRECT at constant $$\mathrm{T}$$ and $$\mathrm{P}$$ ?

Calculate amount of methane formed by liberation of $$149.6 \mathrm{~kJ}$$ of heat using following equation.

$$\mathrm{C}_{(\mathrm{s})}+2 \mathrm{H}_{2(\mathrm{~g})} \longrightarrow \mathrm{CH}_{4(\mathrm{~g})} \quad \Delta \mathrm{H}=-74.8 \mathrm{~kJ} / \mathrm{mol}$$

Calculate $$\Delta \mathrm{S}_{\text {total }}$$ for the following reaction at $$300 \mathrm{~K}$$.

$$\mathrm{NH}_4 \mathrm{NO}_{3(\mathrm{~s})} \longrightarrow \mathrm{NH}_{(\mathrm{aq})}^{+}+\mathrm{NO}_{3(\mathrm{aq})}^{-}$$

$$\left(\Delta \mathrm{H}=28.1 \mathrm{~kJ} \mathrm{~mol}^{-1}, \Delta \mathrm{S}_{\mathrm{sys}}=108.7 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}\right)$$