$S + \frac{3}{2} O_2 \to SO_3 + 2x \ kcal$
$SO_2 + \frac{1}{2} O_2 \to SO_3 + y \ kcal$
Find out the heat of formation of $SO_2$.

Given that $\Delta H_f(H) = 218 \ kJ/mol$, express the $H-H$ bond energy in $kcal/mol$.

If the standard molar enthalpy change for combustion of graphite powder is $-2.48 \times 10^{2} \ kJ \ mol^{-1}$,the amount of heat generated on combustion of $1 \ g$ of graphite powder is $..... \ kJ$.
(Nearest integer)

What is the standard $N \equiv N$ bond enthalpy from the following reaction? $N_{2(g)} + 3H_{2(g)} \longrightarrow 2NH_{3(g)} \quad \Delta H^{\circ} = -83 \ kJ$
Given: $(\Delta H^{\circ}_{(H-H)} = 435 \ kJ \text{ mol}^{-1}, \Delta H^{\circ}_{(N-H)} = 389 \ kJ \text{ mol}^{-1})$

Calculate the enthalpy change of vaporisation of benzene if $13 \ g$ of benzene vaporised by supplying $5.1 \ kJ$ of heat.

The heat of atomisation of methane and ethane are $x \ kJ \ mol^{-1}$ and $y \ kJ \ mol^{-1}$ respectively. The longest wavelength $(\lambda)$ of light capable of breaking the $C-C$ bond can be expressed in $SI$ unit as :