Chapter 7, Problem 100IAE

Interpretation Introduction

Interpretation:

The reason for the different heat of combustion values for hydrogen for the formation of water in liquid and gaseous state needs to be explained.

Concept introduction:

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.