Magnesium sulfate, also known as Epsom salt, bitter salt or bitter sulfur, is an inorganic compound with the chemical formula MgSO4. It is a common magnesium-containing salt, widely used in various industries due to its distinctive physical and chemical properties.
Physically, it is usually colorless or white hygroscopic crystals or fine powder, odorless but with a bitter and saline taste. It has strong deliquescence, absorbing moisture from the air and dissolving gradually in humid environments. Anhydrous magnesium sulfate has a melting point of about 1124℃, while the common heptahydrate form loses crystal water and decomposes at 150℃.
Chemically stable under normal conditions, magnesium sulfate is highly soluble in water (35.1 g per 100 mL at 20℃), slightly soluble in ethanol and insoluble in ether and benzene. Dissolved in water, it dissociates into magnesium and sulfate ions, making the solution slightly acidic. It forms various hydrates, with magnesium sulfate heptahydrate (MgSO4·7H2O) being the most widely used.
Magnesium sulfate has extensive industrial applications. In agriculture, it acts as a magnesium fertilizer to prevent crop magnesium deficiency and improve yield. In medicine, it is used as a laxative and for external anti-inflammatory and analgesic purposes. In industry, it serves as a desiccant for organic solvents and a raw material for magnesium salts, paper and fire retardants. It is also used as a food additive and in environmental water treatment.
product information
| Melting point | 1124 °C |
| density | 1.07 g/mL at 20 °C |
| bulk density | 600kg/m3 |
| vapor density | <0.01 (vs air) |
| vapor pressure | <0.1 mm Hg ( 20 °C) |
| storage temp. | no restrictions. |
| solubility | H2O: 1 M at 20 °C, clear, colorless |
| form | powder (very fine) |
| Specific Gravity | 2.66 |
| color | slightly gray |
| Odor | at 100.00 %. odorless |
| PH | 7.9 (50g/l, H2O, 25℃) |
| Odor Type | odorless |
| Water Solubility | Soluble in water. Slightly soluble in alcohol, glycerol. Insoluble in acetone. |
| Sensitive | Hygroscopic |
| λmax | λ: 260 nm Amax: 0.03 λ: 280 nm Amax: 0.02 |
| Merck | 14,5691 |
| Dielectric constant | 8.2（Ambient） |
| Stability: | Stable. Hygroscopic. |
| LogP | -1.031 (est) |
| CAS DataBase Reference | 7487-88-9(CAS DataBase Reference) |
| NIST Chemistry Reference | Magnesium sulfate(7487-88-9) |
| EPA Substance Registry System | Magnesium sulfate (7487-88-9) |
Safety Information
| Hazard Codes | Xi |
| Risk Statements | 36/37/38 |
| Safety Statements | 22-24/25-36-26 |
| WGK Germany | 1 |
| RTECS | OM4500000 |
| F | 3 |
| TSCA | Yes |
| HS Code | 28332100 |
| Hazardous Substances Data | 7487-88-9(Hazardous Substances Data) |
