Answer:
ΔH3 = -110.5 kJ.
Explanation:
Hello!
In this case, by using the Hess Law, we can manipulate the given equation to obtain the combustion of C to CO as shown below:
C(s) + 1/2O2(g) --> CO(g)
Thus, by letting the first reaction to be unchanged:
C(s) + O2(g)--> CO2 (g) ; ΔH1 = -393.5 kJ
And the second one inverted:
CO2(g) --> CO(g) + 1/2O2(g) ; ΔH2= 283.0kJ
If we add them, we obtain:
C(s) + O2(g) + CO2(g) --> CO(g) + CO2 (g) + 1/2O2(g)
Whereas CO2 can be cancelled out and O2 subtracted:
C(s) + 1/2O2(g) --> CO(g)
Therefore, the required enthalpy of reaction is:
ΔH3 = -393.5 kJ + 283.0kJ
ΔH3 = -110.5 kJ
Best regards!
