The combustion of carbon to form $CO_2$ is given by the equation: $C(s) + O_2(g) \rightarrow CO_2(g)$ For 1 mole of $CO_2$ (molar mass = 44 g/mol), the heat of combustion ($\Delta H$) is $-393.5 \text{ kJ/mol}$. The number of moles in 35.2 g of $CO_2$ is: $n = \frac{\text{Given mass}}{\text{Molar mass}} = \frac{35.2 \text{ g}}{44 \text{ g/mol}} = 0.8 \text{ moles}$ The heat released for the formation of 0.8 moles of $CO_2$ is: $\Delta H = 0.8 \text{ moles} \times (-393.5 \text{ kJ/mol}) = -314.8 \text{ kJ} \approx -315 \text{ kJ}$ .