Question

Using the following equation for the combustion of octane, calculate the heat associated with the formation of 100.0 g of carbon dioxide. The molar mass of octane is 114.33 g/mol. The molar mass of carbon dioxide is 44.0095 g/mol.

Answer 1

Answer: Heat associated with the formation of 100.0 g of carbon dioxide is 1563.2 kJ.

Explanation:

Reaction equation will be as follows.

    $2C_{8}H_{18} + 25O_{2} \rightarrow 16CO_{2} + 18H_{2}O$;  $\Delta H^{o}_{rxn}$ = -11018 kJ

Mass of $CO_{2}$ = 100 g

Hence, moles of $CO_{2}$ present will be calculated as follows.

       No. of moles = $\frac{mass}{\text{molar mass}}$

                             = $\frac{100 g}{44.0095 g/mol}$

                             = 2.27 mol

Therefore, heat produced by 2.27 mol for the given reaction will be calculated as follows.

         $2.27 mol \times \frac{11018 kJ}{16 mol CO_{2}}$

             = 1563.2 kJ

Thus, we can conclude that heat associated with the formation of 100.0 g of carbon dioxide is 1563.2 kJ.