For the reaction \( \mathrm{C_2H_6 \rightarrow C_2H_4 + H_2} \)
the reaction enthalpy \( \Delta_r H = \) __________ \( \mathrm{kJ\,mol^{-1}} \). (Round off to the Nearest Integer).
[Given: Bond enthalpies in \( \mathrm{kJ\,mol^{-1}} \) : C–C : \( 347 \), C = C : \( 611 \); C–H: \( 414 \), H–H : \( 436 \)]
