What is a exothermic reaction?

An exothermic reaction is one where the products have less energy than the starting reactants.  This means the reaction must give out energy, usually in the form of heat or sound.  As a result of this, H (the enthaply of the reaction) must be negative as the reaction has lost energy.

On the other hand if a reaction takes in energy, then it is known as endothermic.  Here, the products have more energy than the reactants, and H will be postive.

Answered by Fraser P. Chemistry tutor

3154 Views

See similar Chemistry GCSE tutors

Related Chemistry GCSE answers

All answers ▸

What is a catalyst?


Why is chlorine more reactive than bromine?


The halogens are elements in Group 7. Bromide is in Group 7. How many electrons are there in the outer shell of a bromine atom? (1 mark)


How can chromatography be used to identify substances?


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo
Cookie Preferences