Energy Transfers in Reactions
An Exothermic Reaction is a reaction that gives out heat. You can tell if a reaction is Exothermic because there will usually be a rise in temperature.
- The best example of an Exothermic Reaction would be burning fuels, or Combustion
An Endothermic Reaction is a reaction that takes in heat. You can tell if a reaction is Endothermic because there will usually be a rise in temperature.
- Endothermic Reactions are much less common, but an example of one would be Thermal Decompositions
Energy Transfers in Reactions 2
Reversible Reactions can be both Exothermic and Endothermic.
- An example of a reaction like this is the Thermal Decomposition of hydrated copper sulfate:
Hydrated copper sulfate = (reversible reaction symbol) anhydrous copper sulfate + water
If you heat blue hydrate copper sulfate crystals, it evaporates the water from it (you can collect this by using a cooling system to condense the water vapor) and leaves white anhydrous copper sulfate crystals. Then when you pour the water back onto the white crystals, they turn back into the blue hydrated copper sulfate crystals.