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) + O2 (g) → CO2 (g) ; ∆r H = x kJ mol–1
(b) C (graphite) + \(\frac{1}{2}\)O2 (g) → CO (g) ; ∆r H = y kJ mol–1
(c) CO (g) + \(\frac{1}{2}\)O2 (g) → CO2 (g) ; ∆r H = z kJ mol–1
1
z = x + y
2
x = y – z
3
x = y + z
4
y = 2z – x