[CH3COOCH5]

Question states: "Methane burns in oxygen to produce carbon dioxide and water.

CH₄ (g) + 2O₂ (g) CO₂ (g) + 2H₂O (g)

Use the following data to calculate the enthalpy of combustion of methane in kJmol-1 .

CH₄ (g) + O₂ (g) ----> CH₂O (g) + H₂O (g) H = -284kJ
CH₂O (g) + O₂ (g) ----> CO₂ (g) + H₂O (g) H = - 518kJ"

Thanks in advance,

CH3COOCH5

[FeLiXe]

add equations (or multiples), subtract things on both sides -> get the sum equation

add the enthalpies (or the corresponding multiples) to get the enthalpy of the sum equation

in this case you just have to add up the two equations (mulitplied by one) to get the sum equation on the top. Its enthalpy equals the sum of the enthalpies.

[CH3COOCH5]

Thanks!