Formation of Calcium Hydroxide

CaO + H2O → Ca(OH)2

Overview

Calcium oxide (quicklime) reacts exothermically with water to form calcium hydroxide (slaked lime). This reaction generates considerable heat and can cause water to boil. It is one of the oldest known chemical reactions, used in construction for millennia.

Participants

Role Substance Coefficient State
Reactant Calcium Oxide CaO 1 (s)
Reactant Water H₂O 1 (l)
Product Calcium Hydroxide Ca(OH)₂ 1 (s)

Everyday Example

Self-heating food cans and chemical heating packs sometimes use this reaction between quicklime and water to generate heat.

Industrial Importance

Calcium hydroxide is used in water treatment, paper manufacturing, sugar refining, and as a component in mortar and plaster. Essential for pH adjustment in many industrial processes.

Properties

Type
Synthesis
Reversible
No
Energy
Exothermic
ΔH
-65.2 kJ/mol

Related Reactions

Fischer-Tropsch Synthesis (General) Formation of Aluminum Oxide Formation of Ammonia (Haber Process) Formation of Barium Oxide Formation of Barium Sulfate Formation of Beryllium Oxide Formation of Cadmium Oxide Formation of Calcium Carbonate from Oxides Formation of Calcium Oxide (Quicklime) Formation of Carbon Dioxide from Elements

Frequently Asked Questions

What is the equation for Formation of Calcium Hydroxide?
The balanced equation is: CaO + H₂O → Ca(OH)₂.
What type of reaction is Formation of Calcium Hydroxide?
Formation of Calcium Hydroxide is a synthesis reaction.
Is Formation of Calcium Hydroxide exothermic or endothermic?
Formation of Calcium Hydroxide is exothermic (releases energy). The enthalpy change (ΔH) is -65.2 kJ/mol.