The standard enthalpies of formation of $\mathrm{CH_4(g)}$, $\mathrm{CO_2(g)}$ and $\mathrm{H_2O(l)}$ are $-78$, $-395$ and $-288\ \mathrm{kJ\ mol^{-1}}$ respectively. Calculate $\Delta H$ for:
\[
\mathrm{2CH_4(g) + 4O_2(g) \rightarrow 2CO_2(g) + 4H_2O(l)}
\]
}