Determine the value of the enthalpy change, $H_{rxn},$ for the following reaction

using the information below.

$2C_2{H}_4(g)4H_2(g)+4C(s)$

$C{F}_4(g)C(s)+2F_2(g)$

$H_2(g)+F_2(g)2HF(g)$

$H=-104\mathrm{.}6kJ$

$H=+680\mathrm{.}0kJ$

$H=-537kJ$