Find the value $\Delta H_f^o[NH_{3(g)}]$ if $\Delta H_r$ for the reaction $N_{2(g)} + 3H_{2(g)} \to 2NH_{3(g)}$ is $-\,183.6 \ kJ/mol$ of $N_{2(g)}$.

Calculate the enthalpy of vaporisation of ethanol if $11.5 \ g$ of ethanol is completely vaporised by supplying $11.8 \ kJ$ of heat.

The enthalpy of neutralization is about $57.3 \ kJ$ for the pair:

The heat of neutralization of four acids $A$,$B$,$C$,and $D$ are $-13.0$,$-12.6$,$-9.2$,and $-11.7 \ KCal/eq$ respectively when neutralized by $NaOH$. The order of acidic strength of the four acids will be:

Identify the molecule for which the enthalpy of atomization $\left(\Delta_{a} H^{\ominus}\right)$ and bond dissociation enthalpy $\left(\Delta_{BOND} H^{\ominus}\right)$ are not equal.

The enthalpies of combustion of $C$(graphite) and $C$(diamond) are $-393.8 \ kJ \ mol^{-1}$ and $-395.3 \ kJ \ mol^{-1}$ respectively. The enthalpy of conversion of $C$(graphite) to $C$(diamond) is