Question

The molar enthalpy of combustion for one mole of propane is -2202 kJ. There are two ways to express this reaction using chemical equations. Write both types of chemical equations for the forward exothermic reaction. Then draw an enthalpy diagram similar to diagram (a) above. Include reactants, products, and the heat of the reaction.

Answer 1

The combustion of propane is an exothermic reaction. The forward (DH =+) and exothermic (DH= -) reactions are as follows:

$\begin{gathered} C_3H_{8(g)}+5O_{2(g)}\text{ }\rightarrow3CO_{2(g)}+4H_2O_{(g)}\text{ }\Delta H=-2202kJ \\ 3CO_{2(g)\text{ }}+4H_2O_{(g)}\text{ }\rightarrow C_3H_{8(g)}+5O_{2(g)}\text{ }\Delta H=+2202kJ \end{gathered}$