When chemical reactions occur…
Energy is transferred to or from the surroundings
What is an exothermic reaction?
One that transfers energy to the surroundings, usually in the form of heat
What are some examples of exothermic reactions?
Combustion, many oxidation reactions and neutralisation
What are some everyday uses for exothermic reactions?
Self-heating cans and hand warmers
What is an endothermic reaction?
One that takes energy from the surroundings, usually in the form of heat
What is an example of an endothermic reaction?
Thermal decompositions
What is an everyday use for an endothermic reaction?
A sports injury pack
If a reversible reaction is exothermic in one direction…
it is endothermic in the opposite direction
What is an example of a reversible reaction, which is endothermic one way
Heat blue hydrated copper sulfate crystals which when the water is dried off leaves white anhydrous copper sulfate powder
What is an example of a reversible reaction, which is exothermic the other way
Add water to the white anhydrous copper sulfate powder to get the blue hydrated copper sulfate crystals back again
