c
આપેલા : \({\mkern 1mu} {\mkern 1mu} \frac{1}{2}{{\text{N}}_{\text{2}}}{\mkern 1mu}  + {\mkern 1mu} {\mkern 1mu} \frac{{\text{3}}}{{\text{2}}}{\mkern 1mu} {{\text{H}}_{\text{2}}}{\mkern 1mu}  \to {\mkern 1mu} {\mkern 1mu} {\text{N}}{{\text{H}}_{\text{3}}}{\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} \Delta {{\text{H}}_{\text{1}}}{\mkern 1mu}  = {\mkern 1mu} {\mkern 1mu} {\text{  -  }}{\mkern 1mu} {\mkern 1mu} {\text{46}}\,{\text{KJ}}\)

\({{\text{H}}_{\text{2}}}{\mkern 1mu}  + {\mkern 1mu} {\mkern 1mu} \frac{{\text{1}}}{{\text{2}}}{{\text{O}}_{\text{2}}}{\mkern 1mu}  \to {\mkern 1mu} {{\text{H}}_{\text{2}}}{\text{O}}{\mkern 1mu} {\mkern 1mu} \Delta {H_2}{\mkern 1mu}  = {\mkern 1mu} {\mkern 1mu} {\text{  -  }}{\mkern 1mu} {\mkern 1mu} {\text{286}}\,{\text{KJ}}\)

\(\,{\text{4N}}{{\text{H}}_{\text{3}}}\, + \,\,{\text{3}}{{\text{O}}_{\text{2}}}\, \to \,\,{\text{2}}{{\text{N}}_{\text{2}}}\, + \,\,{\text{6}}{{\text{H}}_{\text{2}}}{\text{O,}}\,\,\Delta {\text{H}}\,\, = \,\,{\text{?}}\)

\(\begin{gathered}
  \Delta {\text{H}}{\mkern 1mu} {\mkern 1mu}  = {\mkern 1mu} {\mkern 1mu} {\text{6}}\Delta {\mkern 1mu} {{\text{H}}_{\text{2}}}{\mkern 1mu} {\text{  -  }}{\mkern 1mu} {\mkern 1mu} {\text{4}}{\mkern 1mu} \Delta {\mkern 1mu} {{\text{H}}_{\text{1}}}{\mkern 1mu} {\mkern 1mu} {\mkern 1mu}  \hfill \\
   \Rightarrow {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} \Delta {\text{H}}{\mkern 1mu} {\mkern 1mu}  = {\mkern 1mu} {\mkern 1mu} {\text{6(  -  286)}}{\mkern 1mu} {\text{  -  }}{\mkern 1mu} {\text{4}}{\mkern 1mu} {\text{(  -  46)}}{\mkern 1mu} {\mkern 1mu}  \hfill \\
   = {\mkern 1mu} {\mkern 1mu} {\text{  -  }}{\mkern 1mu} {\mkern 1mu} {\text{1716}}{\mkern 1mu} {\mkern 1mu}  + {\mkern 1mu} {\mkern 1mu} {\text{184 }}{\mkern 1mu} {\mkern 1mu}  \hfill \\
  \therefore {\mkern 1mu} {\mkern 1mu} \Delta {\text{H}}{\mkern 1mu} {\mkern 1mu}  = {\mkern 1mu} {\mkern 1mu} {\text{  -  }}{\mkern 1mu} {\mkern 1mu} {\text{1532}}{\mkern 1mu} \,{\text{KJ}} \hfill \\ 
\end{gathered} \)