---
title: "Endothermic Reaction — AP Chem Definition & Exam Guide"
description: "An endothermic reaction absorbs heat, so ΔH > 0 and products sit above reactants on an energy diagram. Key for Le Châtelier shifts and ΔG° on AP Chem."
canonical: "https://fiveable.me/ap-chem/key-terms/endothermic-reaction"
type: "key-term"
subject: "AP Chemistry"
---

# Endothermic Reaction — AP Chem Definition & Exam Guide

## Definition

An endothermic reaction is one that absorbs heat from its surroundings. In this process, more heat goes into breaking bonds in reactants than gets released when new bonds form in products.

## Related Study Guides

- [7.10 Reaction Quotient and Le Châtelier’s Principle](/ap-chem/unit-7/reaction-quotient-le-chateliers-principle/study-guide/JFx1InPfZCZ9SugPKDCE)
- [5.6 Reaction Energy Profile](/ap-chem/unit-5/reaction-energy-profile/study-guide/RF1B5UBHtCp0qgt8ayp3)
- [7.9 Introduction to Le Châtelier’s Principle](/ap-chem/unit-7/intro-le-chateliers-principle/study-guide/ST8UE6kcdhi0hkA5bSkN)
- [9.3 Gibbs Free Energy and Thermodynamic Favorability](/ap-chem/unit-9/gibbs-free-energy-thermodynamic-favorability/study-guide/hCJVI2XJaSGmj1c3zvrO)
- [6.2 Energy Diagrams ](/ap-chem/unit-6/energy-diagrams/study-guide/oASenD5gSuLH8VI0Yrxa)
- [7.14 Free Energy of Dissolution](/ap-chem/unit-7/free-energy-dissolution/study-guide/tsCK6wFJQBajLTmMNv44)

## Review

### Related Terms

- Thermochemistry: The study of energy changes that occur during chemical reactions and changes in state.
- Heat of Reaction/Enthalpy Change: The total amount of heat absorbed or released during a chemical reaction.
- [Exothermic Reaction](/ap-chem/key-terms/exothermic-reaction): A type of chemical process that releases heat into its surroundings, opposite to an endothermic reaction.