Calculate the standard enthalpy of combustion of a methane sample by using the standard enthalpies of formation.

Write the equation and balance it. CH4 + 2O2 --> CO2 + 2H2O Assign the enthalpies of formation and the sign of the energy value with the corresponding molecule (Will demonstrate my technique if needed). e.g. C(s) + 2H2(g) --> CH4(g) Delta H(f) = -74.87

Generate an equation will all assigned values and the single unknown Delta H(combustion/c). Rearrange for Delta H(c). Answer is - 890.63 KJ/mol.