C

Calcium hydroxide

IUPAC: calcium dihydroxide

Ca(OH)2 Bases & Alkalis CAS 1305-62-0
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Quick Reference
Formula / NotationCa(OH)2
CAS Number1305-62-0
Molecular Weight74.09
Melting Point1076 °F (Decomposes) (Loses H2O) (NIOSH, 2024)
Boiling PointDecomposes (NIOSH, 2024)
Density2.24 at 68 °F (USCG, 1999) - Denser than water; will sink
Solubility0.2 % at 32 °F (NIOSH, 2024)
AppearanceCalcium hydroxide is an odorless white granules. Sinks in water. (USCG, 1999)
Also Known Ascalcium dihydroxide; 1305-62-0; Slaked lime; Hydrated lime; Lime hydrate; Calcium hydrate; Lime water; Calcium hydroxide (Ca(OH)2); Hydralime; Slaked-lime
CategoryBases & Alkalis

What is Calcium hydroxide?

Calcium hydroxide (Ca(OH)2) is a base or alkali that appears as Calcium hydroxide is an odorless white granules. Sinks in water. (USCG, 1999). It has a molecular weight of 74.09 g/mol. Its IUPAC name is calcium dihydroxide. Boiling point: Decomposes (NIOSH, 2024). Melting point: 1076 °F (Decomposes) (Loses H2O) (NIOSH, 2024).

Formula & Notation

Ca(OH)2

IUPAC Name: calcium dihydroxide

Other Names / Synonyms: calcium dihydroxide; 1305-62-0; Slaked lime; Hydrated lime; Lime hydrate; Calcium hydrate; Lime water; Calcium hydroxide (Ca(OH)2); Hydralime; Slaked-lime

Properties & Characteristics

Appearance: Calcium hydroxide is an odorless white granules. Sinks in water. (USCG, 1999). Molecular formula: CaH2O2. Molecular weight: 74.09 g/mol. Boiling point: Decomposes (NIOSH, 2024). Melting point: 1076 °F (Decomposes) (Loses H2O) (NIOSH, 2024). Density: 2.24 at 68 °F (USCG, 1999) - Denser than water; will sink. Solubility: 0.2 % at 32 °F (NIOSH, 2024). Vapor pressure: 0 mmHg (approx) (NIOSH, 2024).

Physical Data

PropertyValue
Melting Point1076 °F (Decomposes) (Loses H2O) (NIOSH, 2024)
Boiling PointDecomposes (NIOSH, 2024)
Density2.24 at 68 °F (USCG, 1999) - Denser than water; will sink
Molecular Weight74.09
Solubility0.2 % at 32 °F (NIOSH, 2024)
AppearanceCalcium hydroxide is an odorless white granules. Sinks in water. (USCG, 1999)

Uses & Applications

Used in chemical manufacturing, pH adjustment, saponification, water treatment, and as a laboratory reagent.

Safety Information

Corrosive or irritant. Causes burns to skin and eyes. Store away from acids. Wear protective gloves and goggles. Consult SDS before use.

Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.

Key Facts

Term Calcium hydroxide
Formula Ca(OH)2
CAS Number 1305-62-0
Molecular Weight 74.09
Category Bases & Alkalis
Synonyms calcium dihydroxide; 1305-62-0; Slaked lime; Hydrated lime; Lime hydrate; Calcium hydrate; Lime water; Calcium hydroxide (Ca(OH)2); Hydralime; Slaked-lime

Frequently Asked Questions

Calcium hydroxide (Ca(OH)2) is a base or alkali that appears as Calcium hydroxide is an odorless white granules. Sinks in water. (USCG, 1999). It has a molecular weight of 74.09 g/mol. Its IUPAC name is calcium dihydroxide. Boiling point: Decomposes (NIOSH, 2024). Melting point: 1076 °F (Decomposes) (Loses H2O) (NIOSH, 2024).

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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.