Question

Given that, C + O₂ → CO₂; ΔH° = -x kJ, 2CO + O₂ → 2CO₂; ΔH° = -y kJ. The enthalpy of formation of CO will be

(a) (2x - y)/2

(b) (y - 2x)/2

(c) 2x - y 

(d) y - 2x

Answer 1

Correct option (b) (y - 2x)/2

Explanation:

Divide Eq. (ii) by 2 because heat of formation is calculated for one mole of CO.