C2(ii) - Rates of Reaction 6.

Energy Transfer in Reactions.

Whenever chemical reactions occur energy is usually transferred to or from the surroundings.

In an Exothermic Reaction,  Heat is Given Out.

An EXOTHERMIC reaction is one which gives out energy to the surroundings, usually in the form of heat and usually shown by a rise in temperature.

1) Burning Fuels.

The best example of an exothermic reaction is burning fuels, also called COMBUSTION. This gives out a lot of heat, it's very exothermic.

2) Neutralisation Reactions.

Neutralisation reactions (acid + alkali) are also exothermic.

3) Oxidation Reactions.

Many oxidation reactions are exothermic.

Addition of water to anhydrous copper(II) sulphate to turn into blue hydrated copper sulphate crystals produces heat, so it must be exothermic.

(Anhydrous just means without water and hydrated means with water.)

In an Endothermic Reaction, Heat is Taken…