Energetics - (CCEA)Endothermic reactions

When a chemical reaction occurs, energy is transferred to, or from, the surroundings. An exothermic reaction releases heat to the surroundings and an endothermic reaction absorbs heat from the surroundings.

Part ofCombined ScienceMetals and the reactivity series

Endothermic reactions

An reaction takes in energy from its surroundings. The temperature of its surroundings decreases.

The reaction between sodium hydroxide and hydrochloric acid is exothermic.

The reaction between sodium carbonate and ethanoic acid is endothermic.

An exothermic reaction between dilute sodium hydroxide and hydrochloric acid.

Image gallerySkip image gallerySlide1 of 4, Sodium hydroxide solution is poured into a beaker of hydrochloric acid which contains a thermometer showing room temperature, 1. Sodium hydroxide solution is poured into a beaker of hydrochloric acid. Inside is a thermometer showing room temperature.