On the basis of t A. z = x + y

B. x = y – z

C. x = y + z

D. y = 2z – x

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