What is enthalpy?

Enthalpy (given the symbol H) is a measure of how much heat energy can be released by a chemical. ΔH is defined as the amount of heat energy released or taken in when two chemicals react. If ΔH is negative it means that the reaction is exothermic and will give out heat as it progresses and will feel hot.

If ΔH is positive then the reaction is endothermic and will therefore absorb heat as it progresses, and will feel cold.

Chris M. GCSE Chemistry tutor, A Level Chemistry tutor, GCSE Biology ...

6 months ago

Answered by Chris, an A Level Chemistry tutor with MyTutor

Still stuck? Get one-to-one help from a personally interviewed subject specialist


PremiumKonrad E. GCSE Chemistry tutor, GCSE Biology tutor, A Level Chemistry...
View profile
£26 /hr

Konrad E.

Degree: Natural Sciences: Physical (Masters) - Cambridge University

Subjects offered: Chemistry, Physics+ 2 more

Further Mathematics

“I'm studying Natural Sciences (Phys) at Cambridge. I enjoy tutoring science and maths at GCSE and A-Level, and sharing my experience.”

PremiumEls  D. Uni Admissions Test .BMAT (BioMedical Admissions) tutor, Ment...
View profile
£30 /hr

Els D.

Degree: Veterinary Science BVSC (Bachelors) - Bristol University

Subjects offered: Chemistry, Science+ 4 more

.BMAT (BioMedical Admissions)
-Personal Statements-

“Often students are too shy to ask questions in the classroom - and this can be detrimental to their learning. During my own studies at both GCSE and A-Level, I found one to one tutition to be invaluable in helping me get to grips with all those...”

Jonathan B. A Level Chemistry tutor, GCSE Chemistry tutor, A Level Ma...
View profile
£20 /hr

Jonathan B.

Degree: Chemistry (Masters) - Oxford, Lincoln College University

Subjects offered: Chemistry, Physics+ 1 more


“Hi, my name is Jonny and I have just finished my first year studying Chemistry at Oxford University, taking modules inChemistry, Physics and Maths. I have experience tutoring secondary school maths and science students and I have a pa...”

About the author

Chris M. GCSE Chemistry tutor, A Level Chemistry tutor, GCSE Biology ...
View profile
£20 /hr

Chris M.

Degree: MChem (Masters) - Oxford, St Catherine's College University

Subjects offered: Chemistry, Biology


“Hey,You've made it this far, now read a little about me and what you can expect, and hopefully get in touch.About me:I am reading chemistry at Oxford University and am currently working on a project to design a new type of spectr...”

MyTutor guarantee

You may also like...

Posts by Chris

What are the different types of bonding in chemicals?

What is an isotope?

What is enthalpy?

What is le Chatelier's principle?

Other A Level Chemistry questions

Explain electrophilic aromatic substitution?

what is a simple test to detect the presence of a carbonyl and to identify it?

Explain the trend in Ionisation energy when moving across a period and down a group

What are the different forms of elemental carbon?

View A Level Chemistry tutors


We use cookies to improve our service. By continuing to use this website, we'll assume that you're OK with this. Dismiss