The enthalpy change for the reaction between W(s) and C(graphite) is difficult to measure directly because the reaction occurs at 1400degree C
W(s) + C(graphite) -- WC(s)
However the heats of combustion of the elements and of tungsten carbide can be measured and are given below:
2W(s) + 3O2(g)--2WOcube(S) delta H = -1680.6kJ
C(graphite) + O2(g) -- CO2(g) delta H = -393.5kJ
2WC(S) + 5O2(g) -- 2WO3(s) +2CO2(g) delta H +-2391.6kj