Chemistry · Ch 4 — Chemical Thermodynamics

Enthalpy of chemical reaction (ΔrH)

4.10.1

Consider the reaction

a\mathrm{A} + b\mathrm{B} \longrightarrow c\mathrm{C} + d\mathrm{D}

The enthalpy change for the reaction is

\Delta_r H = (cH_C + d\,H_D) - (a\,H_A + bH_B)

where $H_A$ , $H_B$ , $H_C$ and $H_D$ are the molar enthalpies of A, B, C and D, respectively. We write

$\Delta_r H = \sum H_{products} - \sum H_{reactants} \qquad \text{...(4.29)}$ …