Question:
On the basis of thermochemical equations (a), (b) and (c), find out which of the
algebraic relationships given in options (i) to (iv) is correct.
(a) C (graphite) + O2 (g) → CO2 (g) ; ∆rH = x kJ mol–1
(b) C (graphite) +12 O2 (g) → CO (g) ; ∆rH = y kJ mol–1
(c) CO (g) +12 O2 (g) → CO2 (g) ; ∆rH = z kJ mol–1
(i) z = x + y
(ii) x = y – z
(iii) x = y + z
(iv) y = 2z – x
Solution:
Option (iii) x = y + z is the answer.