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Chemistry vocabulary · Energy, Reaction Rates and Equilibrium

Endothermic

Meaning in chemistry, with examples

/ˌendəʊˈθɜːmɪk/adjectiveCore term

In chemistry, endothermic means: Describes a reaction or process that takes in heat from the surroundings, so the surroundings get colder. Its enthalpy change (ΔH) is positive.

In Turkish: endotermik, ısı alan

How it is used

Used with energy diagrams and in thermochemistry. Melting, evaporation, thermal decomposition and photosynthesis are endothermic. Instant cold packs work because dissolving ammonium nitrate is endothermic.

Example sentences

  1. The decomposition of calcium carbonate is endothermic, so it needs strong heating.

  2. The beaker felt cold, which shows that the dissolving process is endothermic.

Common collocations

  • endothermic reaction
  • endothermic process
  • slightly endothermic
  • exothermicDescribes a reaction or process that releases heat to the surroundings, so the temperature rises. Its enthalpy change (ΔH) is negative.
  • enthalpyThe heat content of a system at constant pressure. Chemists usually measure its change, ΔH, which shows how much heat a reaction gives out or takes in.
  • activation energyThe minimum energy that reacting particles need to collide successfully and start a reaction. Catalysts work by lowering it.

This word in other fields

The same English word can have a different meaning in another field:

More terms: Energy, Reaction Rates and Equilibrium

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