Exothermic Reactions
Chemistry: AQA GCSE Higher, topic 5.1.2
Exothermic Reactions
In exothermic reactions, energy from the reacting chemicals is transferred to the surroundings. This often leads to an increase in temperature. Examples include:
Combustion
Neutralisation
Oxidation
Hand warmers
- Disposable hand warmers use the energy released by iron oxidation.
- Reusable hand warmers source their energy from the crystallisation of salt solutions. Boiling the pack re-dissolves the crystals, so that it's ready to be activated once more.
Test yourself on Exothermic Reactions
What type of reaction happens when iron reacts with oxygen to produce heat in a hand warmer?
What type of reaction is shown by an exploding pumpkin releasing heat into its surroundings?
Why are combustion, neutralisation and oxidation all classed as exothermic reactions?
Why does boiling a reusable hand warmer allow it to be used again?