Question

The standard heats of formation of CO(g) and H2O(g) at 25°C are 100.5 kJ and –241.8 kJ per mole

respectively. Calculate the heat change of the following reaction at this temperature.

H2O(g) + C(s) → H2(g) + CO(g)

​

Answer 1

Answer:

△H=H

f

∘

(products)−H

f

∘

(reactants)

Reactants are: CO

2

H

2

and products are CO and H

2

O

Hence,

ΔH =−100.5+(−241.8)−(−393.5+0)=41.2 kJ