Question

What is the enthalpy change when 2.5 moles of methane are burned completely in excess oxygen gas, given that the enthalpy of combustion of methane is -890 kJ/mol?

Answer 1

To calculate the enthalpy change for the combustion of 2.5 moles of methane, you can use the following formula:Enthalpy change = moles of methane  enthalpy of combustion per moleEnthalpy change = 2.5 moles   -890 kJ/mol Enthalpy change = -2225 kJSo, the enthalpy change when 2.5 moles of methane are burned completely in excess oxygen gas is -2225 kJ.