Chapter 14, Problem 14.28P

Interpretation Introduction

Interpretation:

The value of $\Delta H{°}_{\text{rxn}}$ for following reaction has to be determined.

  ${\text{2Cu}}_{\text{2}}\text{O}\left(s\right)+{\text{O}}_{\text{2}}\left(g\right)\to \text{4CuO}\left(s\right)$

Concept Introduction:

Thermodynamics is a study of energy transfers that can be done by either heat or work. The energy transferred through work involves force. When work is positive then system gains energy while when work is negative then system loses energy. Heat is not a state function and therefore change in enthalpy of reaction $\left(\Delta H{°}_{\text{rxn}}\right)$ has been introduced. The expression to calculate $\Delta H{°}_{\text{rxn}}$ is as follows:

  $\Delta H_{\text{rxn}}=H_{\text{prod}}-H_{\text{react}}$

The useful property of $\Delta H{°}_{\text{rxn}}$ is that it is an additive property.