Energy changes

Exothermic

Reaction in which heat energy is given off

Endothermic

Reaction that absorbs heat

Temperature change in exothermic reactions

Temperature increases

Temperature change in endothermic reactions

Temperature decreases

Enthalpy

The heat content of a system

Conservation of energy

Energy cannot be created or destroyed; it may be transformed from one form into another

Uses of exothermic reactions

Self

Self

heating can

Uses of endothermic reactions

Sports injury packs

Sports injury packs

An instant cool pack for treating an injury

Types of exothermic reactions

Combustion, oxidation, neutralisation, displacement

Types of endothermic reactions

Thermal decomposition, Sodium hydrogen carbonate reacting with citric acid

Reactivity and energy changes

The bigger the difference in reactivity in a displacement reaction, the more exothermic the reaction.

Amount of energy in the universe

Does not change during a reaction