On the basis of thermochemical equations (a), (b) and (c), find out which of the algebric relationships given in options (I) to (iv) is correct. (a) C (graphite) + O 2 (g) → CO 2 (g); Δ r H = x kJ mol –1 (b) C (graphite) + O 2 (g) → CO (g); Δ r H = y kJ mol – 1 c) CO (g) + O 2 (g) → CO 2 (g); Δ r H = z kJ mol –1

Question

Philoid · Accepted Answer

Reason:

C (graphite) + O₂ (g) → CO₂ (g); Δ_rH = x kJ mol^–1..…(i)

C (graphite) + O₂ (g) → CO (g);Δ_rH = y kJ mol ^–¹……(ii)

CO (g) + O₂ (g) → CO₂ (g);Δ_rH = z kJ mol^–1 ……(iii)

Adding (ii) and (iii) will be result in equation (I)

Which means that y + z = x