Question

The following two reactions are known

Fe₂O_3(g) + 3CO_(g) → 2Fe_(s) + 3CO_2(g) ;   ΔH = -26.8 kJ

Fe₂O_3(s) + CO_(g) → Fe_(s) + CO_2(g) ; ΔH = -16.5 kJ

The value of ΔH for the following reaction

Fe₂O_3(s) + CO_(g) → 2Fe_(s) + CO_2(g) is 

(a) + 10.3 kJ

(b) - 43.3 kJ

(c) - 10.3 kJ

(d) + 6.2 kJ

Answer 1

The correct option is : (d) + 6.2 kJ

Explanation:

Eq. (iii) can be obtained as :

(i) - 2(ii)

= - 26.8 - 2(-16.5) = -26.8 + 33.0 = + 6.2 kJ