Primjer iz kemije $$\ce{C6H12O6(s) + 6O2(g) -> 6CO2(g) + 6H2O(l)}$$ $\Delta_f H^\circ (\ce{C6H12O6(s)}) = -1273.3 \text{ kJ/mol}$ $\Delta_f H^\circ (\ce{CO2(g)}) = -393.5 \text{ kJ/mol}$ $\Delta_f H^\circ (\ce{H2O(l)}) = -285.8 \text{ kJ/mol}$ $$\Delta_r H^\circ = \sum \Delta_f H^\circ (\text{produkti}) - \sum \Delta_f H^\circ (\text{reaktanti})$$