The reaction of cyanamide, ${\mathrm{NH}}_2\mathrm{CN}\left(\mathrm{s}\right)$ with oxygen was run in a bomb calorimeter and $\mathrm{\Delta }U$ at 300 K was found to be $-743 \mathrm{kJ} {\mathrm{mol}}^{-1}$. The value of $\mathrm{\Delta }H$ at 300 K for the combustion reaction.

${\mathrm{NH}}_2\mathrm{CN}\left(\mathrm{s}\right)+\frac{3}{2}{\mathrm{O}}_2\left(\mathrm{g}\right)\to {\mathrm{N}}_2\left(\mathrm{g}\right)+{\mathrm{CO}}_2\left(\mathrm{g}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)$

would be