Magnesium hydroxide
| Names | |
|---|---|
| IUPAC name Magnesium hydroxide | |
| Other names 
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| Identifiers | |
| 3D model (JSmol) | |
| ChEMBL | |
| ChemSpider | |
| DrugBank | |
| ECHA InfoCard | 100.013.792 | 
| EC Number | 
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| E number | E528 (acidity regulators, ...) | 
| 485572 | |
| KEGG | |
| PubChem CID | |
| RTECS number | 
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| UNII | |
| CompTox Dashboard (EPA) | |
| 
 | |
| 
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| Properties | |
| Mg(OH)2 | |
| Molar mass | 58.3197 g/mol | 
| Appearance | White solid | 
| Odor | Odorless | 
| Density | 2.3446 g/cm3 | 
| Melting point | 350 °C (662 °F; 623 K) decomposes | 
| 
 | |
| Solubility product (Ksp)  | 5.61×10−12 | 
| −22.1×10−6 cm3/mol | |
| Refractive index (nD) | 1.559 | 
| Structure | |
| Hexagonal, hP3 | |
| P3m1 No. 164 | |
| a = 0.312 nm, c = 0.473 nm | |
| Thermochemistry | |
| Heat capacity (C) | 77.03 J/mol·K | 
| Std molar entropy (S⦵298) | 64 J·mol−1·K−1 | 
| Std enthalpy of formation (ΔfH⦵298) | −924.7 kJ·mol−1 | 
| Gibbs free energy (ΔfG⦵) | −833.7 kJ/mol | 
| Pharmacology | |
| A02AA04 (WHO) G04BX01 (WHO) | |
| Hazards | |
| GHS labelling: | |
| Warning | |
| H315, H319, H335 | |
| P261, P280, P304+P340, P305+P351+P338, P405, P501 | |
| NFPA 704 (fire diamond) | |
| Flash point | Non-flammable | 
| Lethal dose or concentration (LD, LC): | |
| LD50 (median dose) | 8500 mg/kg (rat, oral) | 
| Safety data sheet (SDS) | External MSDS | 
| Related compounds | |
| Other anions | Magnesium oxide | 
| Other cations | |
| Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references | |
Magnesium hydroxide is an inorganic compound with the chemical formula Mg(OH)2. It occurs in nature as the mineral brucite. It is a white solid with low solubility in water (Ksp = 5.61×10−12). Magnesium hydroxide is a common component of antacids, such as milk of magnesia.