I
Ion Product For Water
AllChemicals — The Online Chemical Glossary | https://allchemicals.info/chemical/522-ion-product-for-water
What is Ion Product For Water?
The ion product for water (Kw) is the equilibrium constant for the autoionization of water: 2H₂O ⇌ H₃O⁺ + OH⁻, expressed as Kw = [H₃O⁺][OH⁻]. At 25°C, Kw = 1.0 × 10⁻¹⁴, which defines the pH scale: in pure water, [H⁺] = [OH⁻] = 1.0 × 10⁻⁷ M (pH = 7.0). Kw increases with temperature, reflecting the endothermic nature of water autoionization.
Key Facts
Term
Ion Product For Water
Index
All "I" terms
Frequently Asked Questions
The ion product for water (Kw) is the equilibrium constant for the autoionization of water: 2H₂O ⇌ H₃O⁺ + OH⁻, expressed as Kw = [H₃O⁺][OH⁻]. At 25°C, Kw = 1.0 × 10⁻¹⁴, which defines the pH scale: in pure water, [H⁺] = [OH⁻] = 1.0 × 10⁻⁷ M (pH = 7.0). Kw increases with temperature, reflecting the endothermic nature of water autoionization.
More "I" Terms
Ibuprofen
C13H18O2
Ideal Gas
Ideal Gas Law
PV = nRT | R = 8.314 J/(mol·K)
Ideal Solution
Ideal solution: Raoult's law holds; ΔH_mix = 0, ΔV_mix = 0
Ideal Solution
Imidazole
C3H4N2
Indicator
Visual pH/endpoint indicator; e.g., phenolphthalein: colourless (acid) → pink (base)
Indicators
Indium
In
Indole
C8H7N
Induced Dipole
Induced dipole: α × E (α = polarisability; E = electric field)
Inert Gas
View all "I" terms →
Editorial standards: Chemical data is sourced from peer-reviewed literature,
CAS Registry, NIST WebBook, and PubChem. Safety information reflects guidance from OSHA, ECHA,
and IAEA. For educational purposes only — always consult official SDS documentation and qualified
professionals before handling chemicals.