To calculate the enthalpy change for the combustion of propane C3H8 , we need to consider the balanced chemical equation for the combustion reaction and the standard enthalpies of formation for each compound involved.The balanced chemical equation for the combustion of propane is:C3H8 g + 5O2 g 3CO2 g + 4H2O l Now, we need the standard enthalpies of formation Hf for each compound:Hf [C3H8 g ] = -103.85 kJ/molHf [O2 g ] = 0 kJ/mol since it is in its standard state Hf [CO2 g ] = -393.5 kJ/molHf [H2O l ] = -285.8 kJ/molUsing the formula for enthalpy change:H = nHf products - nHf reactants H = [3 -393.5 + 4 -285.8 ] - [ -103.85 + 5 0 ]H = -1180.5 - 1143.2 - -103.85 H = -2323.7 + 103.85H -2219.85 kJ/molThe enthalpy change for the combustion of propane is approximately -2219.85 kJ/mol. This value is negative, indicating that the reaction is exothermic releases heat .