Find δh°rxn for the reaction ch4(g) + 2o2(g) → co2(g) + 2h2o(l). [δh°f (ch4(g)) = –74.8 kj/mol; δh°f (co2(g)) = –393.5 kj/mol; δh°f (h2o(l)) = –285.5 kj/mol]