Solution

$$C(s)\, +\, O_2(g)\, \rightarrow\, CO_2(g);\quad \Delta H\, =\,

-\,94.3$$ kcal/mol ......(1)

$$CO(g)\, +\, 1/2\, O_2(g)\, \rightarrow\, CO_2(g);\quad\Delta
H\, =\, -\,67.4$$ kcal/mol ......(2)

$$O_2(g)\, \rightarrow\, 2O(g);\quad \Delta H\, =\, 117.4$$ kcal/mol ......(3)

$$CO(g)\, \rightarrow\, C(g)\, +\, O(g);\quad \Delta H\, =\,
230.6$$ kcal/mol ......(4)

$$\Delta H$$ for $$C (s)$$ $$\rightarrow$$ $$C(g)$$ ......(5)

Add equations 1 and 4 and from the result, substract equation 2. Divide equation 3 with 2 and substract it from above result to obtain equation 5.

$$\displaystyle \Delta H = -\,94.3 \ kcal/mol+ 230.6 \ kcal/mol -
(-\,67.4 \ kcal/mol) - \dfrac { 117.4 \ kcal/mol}{2}$$

$$\displaystyle \Delta H =145 \ kcal/mol$$