Given : $\Delta {{\rm{H}}^ \ominus }{\rm{ sub }}$ $[{\rm{C }}({\rm{graphite}})] = 710\;{\rm{kJ}}\;{\rm{mo}}{{\rm{l}}^{ - 1}}$
${\Delta _{{\rm{C}} - {\rm{H}}}}{{\rm{H}}^ \ominus } = 414\;{\rm{kJ}}\;{\rm{mo}}{{\rm{l}}^{ - 1}}$
${\Delta _{{\rm{H}} - {\rm{H}}}}{{\rm{H}}^ \ominus } = 436\;{\rm{kJ}}\;{\rm{mo}}{{\rm{l}}^{ - 1}}$
${\Delta _{{\rm{C = C}}}}{{\rm{H}}^ \ominus } = 611\;{\rm{kJ}}\;{\rm{mo}}{{\rm{l}}^{ - 1}}$
The $\Delta {\rm{H}}_{\rm{f}}^ \ominus $ for ${\rm{C}}{{\rm{H}}_2} = {\rm{C}}{{\rm{H}}_2}$ is _____ ${\rm{kJmo}}{{\rm{l}}^{ - 1}}$ (nearest integer value)