Chapter 7, Problem 109IAE

Interpretation Introduction

Interpretation:

The heat of combustion of heptane ${\text{C}}_{\text{7}}{\text{H}}_{\text{16}}\left(l\right)$ is needs to be determined.

Concept introduction:

The combustion of hydrocarbon takes place in the presence of oxygen and results in the formation of carbon dioxide and water.

For example, the combustion of methane gas is represented as follows:

${\text{CH}}_{\text{4}}\left(g\right)+{\text{O}}_2\left(g\right)\to {\text{CO}}_{\text{2}}\left(g\right)+{\text{H}}_{\text{2}}\text{O}\left(g\right)$

The enthalpy of reaction can be calculated using the following relation.

$\Delta H_{rxn}={\displaystyle \sum n_p\Delta H_f\left(\text{products}\right)-{\displaystyle \sum n_r\Delta H_f\left(\text{reactants}\right)}}$

Here, $\Delta H_f\left(\text{products}\right)$ is change in enthalpy of formation of product, $n_p$ is number of moles of product, $\Delta H_f\left(\text{reactants}\right)$ is change in enthalpy of formation of reactant and $n_r$ is number of moles of reactant.