Electrolysis of Water

2H2O → 2H2 + O2

Aperçu

An electric current passed through water splits it into hydrogen gas at the cathode and oxygen gas at the anode. The minimum voltage required is 1.23 V (thermodynamic), but practical electrolyzers operate at 1.8–2.0 V due to overpotential. A small amount of electrolyte (acid, base, or salt) is needed to make water conductive.

Participants

Rôle Substance Coefficient État
Réactif Water H₂O 2 (l)

Exemple du quotidien

Green hydrogen production uses renewable electricity to electrolyze water, producing clean fuel for vehicles and industry.

Importance industrielle

Water electrolysis produces about 4% of the world's hydrogen. Green hydrogen from electrolysis is projected to reach $1.5/kg by 2030.

Propriétés

Type
Electrochemical
Réversible
Oui
Énergie
Endothermique
ΔH
572,0 kJ/mol

Réactions associées

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Frequently Asked Questions

What is the equation for Electrolysis of Water?
The balanced equation is: 2H₂O → 2H₂ + O₂.
What type of reaction is Electrolysis of Water?
Electrolysis of Water is a electrochemical reaction. It is reversible under certain conditions.
Is Electrolysis of Water exothermic or endothermic?
Electrolysis of Water is endothermic (absorbs energy). The enthalpy change (ΔH) is 572.0 kJ/mol.