Thermodynamics

Find standard enthalpy of formation of ammonia from following reaction.

\(\mathrm{N}_{2(\mathrm{~g})}+3 \mathrm{H}_{2(\mathrm{~g})} \longrightarrow 2 \mathrm{NH}_{3(\mathrm{~g})} ; \Delta_{\mathrm{r}} \mathrm{H}^0=-92.0 \mathrm{~kJ}\)