---
title: "Enthalpy of Combustion — AP Chem Definition & Exam Guide"
description: "Enthalpy of combustion (ΔH°comb) is the heat released when one mole of a substance burns completely in oxygen. A core Unit 6 exothermic process tested through calorimetry FRQs."
canonical: "https://fiveable.me/ap-chem/key-terms/enthalpy-of-combustion"
type: "key-term"
subject: "AP Chemistry"
---

# Enthalpy of Combustion — AP Chem Definition & Exam Guide

## Definition

The enthalpy of combustion refers to the amount of heat released or absorbed when one mole of a substance undergoes complete combustion. It is a measure of the energy content in the bonds of the substance.

## Review

### Related Terms

- Heat of Formation: The heat change that occurs when one mole of a compound is formed from its elements in their standard states.
- Standard Enthalpy Change: The enthalpy change that occurs when reactants in their standard states are converted into products in their standard states.
- [Exothermic Reaction](/ap-chem/key-terms/exothermic-reaction): A chemical reaction that releases energy to its surroundings, usually in the form of heat.