Answer:
−26.4 kcal
Explanation:
According to Hess's law, the total heat changes occuring during a chemical reaction are independent of path.
2CO(g)+O
2
(g)⟶2CO
2
(g)N ,
ΔH=−135.2 kcal
The above reaction is reversed and halved, we get-
CO
2
(g)⟶CO+
2
1
O
2
(g)
ΔH=
2
135.2
kcal ....(i)
C+O
2
(g)⟶CO
2
(g)
ΔH= -94 kcal ...(ii)
Required equation
C(s)+
2
1
O
2
(g)⟶CO(g);
Adding Eqs. (i) and (ii), we get
C(s)+
2
1
O
2
(g)⟶CO(g),
ΔH =
2
135.2
−94=−26.4 kcal
