Here's how to determine if it's exothermic or endothermic:

* Exothermic reactions release heat into the surroundings. This is indicated by a negative change in enthalpy (ΔH).

* Endothermic reactions absorb heat from the surroundings. This is indicated by a positive change in enthalpy (ΔH).

In your equation, the 2220 kJ is on the product side. This means that 2220 kJ of energy are released during the reaction.

Therefore, the combustion of propane is an exothermic reaction.