During some reactions, energy is transferred from the surroundings. This is called an endothermic reaction.
In endothermic reactions, energy enters. In exothermic reactions, energy exits.
The change in temperature indicates how exothermic or endothermic the reaction is.
|Increase in temperature||Exothermic|
|Decrease in temperature||Endothermic|
The slideshow describes an exothermic reaction between dilute sodium hydroxide and hydrochloric acid, and an endothermic reaction between sodium carbonate and ethanoic acid.