on Given that

$H_2(g)+F_2(g)longrightarrow2HF(g),H_{rxn}=-546\mathrm{.}6kJ$

$2H_2(g)+O_2(g)longrightarrow2H_{2}O(l),H_{rxn}=-571\mathrm{.}6kJ$

calculate the value of $H_{rxn}$ for

$2F_2(g)+2H_{2}O(l)longrightarrow4HF(g)+O_2(g)$

$H_{rXn}=$