P: 97 Hi, first you need a balanced reaction eq with air $$CH_4 + 2O_2 + 7,43N_2 => CO_2+2H_2O+7,43N_2$$ then you can use this relation; $T_f=T_o+\frac{n\Delta H_c}{\Sigma nC_p}$ where T_f is Adiabatic flame temperature T_o : 298 K, n: nb of moles and $$\Delta H_c$$is heat of combustion of methane and $$\Sigma nC_p$$ is the thermal capacities of RHS, thus: $$1*C_p(CO_2)+2C_p(H_2O)+7,43C_p(N_2)$$ --------------------------------------------------------------------------------