Calculate the enthalpy change for reaction $($a$),$ given the data in equations $($b$),($c$),$ and $($d$).$

$($a$)$

$($b$)$

$2C(graphite)+2H_2(g)longrightarrow{C}_2{H}_4(g)$

$($c$)$

$C(graphite)+O_2(g)longrightarrowC{O}_2(g).$

$H=?$

$($d$)$

$C_2{H}_4(g)+3O_2(g)longrightarrow2C{O}_2(g)+2H_{2}O(l)$

$H_2(g)+\frac{1}{2}{O}_2(g)longrightarrow{H}_{2}O(l)$

$H=-393\mathrm{.}5kJ$

$H=-1410\mathrm{.}9kJ$

$H=-285\mathrm{.}8kJ$