Calculate the enthalpy change for the reaction
$H_2 + F_2 \longrightarrow 2HF$
given that
Bond energy of $H-H$ bond $= 434 \ kJ/mol$
Bond energy of $F-F$ bond $= 158 \ kJ/mol$
Bond energy of $H-F$ bond $= 565 \ kJ/mol$
Result in $kJ$.

When $4 \ g$ of iron is burnt to ferric oxide at constant pressure,$29.28 \ kJ$ of heat is evolved. What is the enthalpy of formation of ferric oxide in $kJ \ mol^{-1}$? (At. Wt. of $Fe = 56$)

According to the following figure,the magnitude of the enthalpy change of the reaction $A+B \rightarrow M+N$ in $kJ \ mol^{-1}$ is equal to ...... .

If the heat of neutralization of an acid-base reaction is $56 \ kJ \ mol^{-1}$,then the substances could be:

Which of the following equations correctly represents the standard heat of formation $(\Delta H_f^o)$ of methane?

At $298 \ K$,the enthalpy of fusion of a solid $(X)$ is $2.8 \ kJ \ mol^{-1}$ and the enthalpy of vaporisation of the liquid $(X)$ is $98.2 \ kJ \ mol^{-1}$. The enthalpy of sublimation of the substance $(X)$ in $kJ \ mol^{-1}$ is $.....$ (in nearest integer).