Exothermicity
| Formula / Notation | ΔH < 0; q_p < 0 (heat released) |
|---|---|
| Also Known As | Exothermic character; heat release; negative enthalpy change; ΔH < 0; exothermal; heat-releasing reaction |
What is Exothermicity?
Exothermicity refers to the property of a reaction or process that releases heat to the surroundings. An exothermic reaction has a negative enthalpy change (ΔH < 0), meaning the products have lower energy than the reactants. The surroundings warm up as heat flows out of the system. Exothermicity is the opposite of endothermicity. Most combustion and neutralisation reactions are exothermic.
Formula & Notation
Other Names / Synonyms: Exothermic character; heat release; negative enthalpy change; ΔH < 0; exothermal; heat-releasing reaction
Properties & Characteristics
Uses & Applications
Safety Information
Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.
Key Facts
Frequently Asked Questions
Exothermicity refers to the property of a reaction or process that releases heat to the surroundings. An exothermic reaction has a negative enthalpy change (ΔH < 0), meaning the products have lower energy than the reactants. The surroundings warm up as heat flows out of the system. Exothermicity is the opposite of endothermicity. Most combustion and neutralisation reactions are exothermic.
Hot packs (exothermic crystallisation of sodium acetate); heat generation in industrial processes; combustion for energy generation; neutralisation in acid spill treatment; hand warmers; welding (thermite reaction)
No direct hazard from the concept. Highly exothermic reactions (thermite, explosions, strong acid-base mixing) can cause thermal burns, fires, or explosions. Uncontrolled exothermic reactions (thermal runaway) are a major industrial hazard.
The formula or notation for Exothermicity is: ΔH < 0; q_p < 0 (heat released)