Question

Calculate ΔH for the reaction given the following thermochemical equation:
2CO₂+O₂→2CO₂

Clue:C+O₂→CO₂ ΔH= -393.5 Kj/mol
C+1/2 O₂→CO ΔH= -110.5 Kj/mol

Answer 1

CO₂(g) → CO(g) + ½O₂;  Δ H = +294 kJ

That means that we also change the sign of ΔH and divide by 2.

Then we add equations 1 and 3 and their ΔH values.

This gives

C(s) +½O₂(g) → CO(g);  Δ H = -99 kJ

Using your numbers, the standard enthalpy of formation of carbon monoxide is -99 kJ/mol.

I think that your value for the heat of combustion of CO is incorrect. It should be -566 kJ.

This would give the correct value of -110 kJ for the heat of formation of CO.

Answer 2

$\boxed{Explained\:Answer}$

______________________________