To determine whether each process is endothermic or exothermic, we look at whether the system absorbs or releases heat.
-
A fire (the system is the fire):
- Exothermic: A fire releases heat into the surroundings as a result of combustion. Therefore, it is considered an exothermic process.
-
A car engine (the system is the engine):
- Exothermic: A car engine burns fuel which generates heat as a byproduct of combustion. This heat is released into the environment, making the process exothermic.
-
A melting ice sculpture (the ice is the system):
- Endothermic: When ice melts, it absorbs heat from its surroundings to change from solid to liquid. Therefore, the melting of the ice sculpture is an endothermic process.
In summary:
- Fire: Exothermic
- Car engine: Exothermic
- Melting ice sculpture: Endothermic