Magnesium sulfate heptahydrate, also known as Epsom salt or bitter salt, is an important inorganic chemical product, characterized as follows:

### Chemical Properties * **Molecular Formula and Molecular Weight**: The chemical formula for magnesium sulfate heptahydrate is MgSO4·7H2O, with a relative molecular mass of 246.47 (some sources may show 246.48, which could be due to calculation accuracy or standard variations).

* **Appearance and Shape**: It is usually a colorless or white needle-like or prismatic crystalline solid, with aggregates showing a glassy luster in white, pink, or green. Odorless, cool, and slightly bitter.

### Physical Properties * **Density and Specific Gravity**: The density is approximately 2.66 grams/cm³ (with some sources reporting 2.57 grams/cm³ or a specific gravity of 1.67~1.71), depending on specific conditions and measurement methods.

Magnesium sulfate heptahydrate is easily soluble in water, slightly soluble in glycerin, and its solution is neutral.

* **Stability**: Stable in humid air below 48.1°C, but prone to weathering into a powdery form in warm, dry air. Decomposes upon heating, gradually losing its crystalline water to become anhydrous magnesium sulfate.

### Versatile Uses of Magnesium Sulfate Heptahydrate Magnesium sulfate heptahydrate has a wide range of applications, primarily including:

* **Agriculture**: Serving as fertilizer, it provides magnesium and sulfur to crops, promoting growth and high yields.

* **Industry**: Used in the manufacturing of leather, dyeing (such as a weighting agent for fine cotton fabrics and silk, and a filler for cotton products), catalysts, papermaking, plastics, ceramics, pigments, matches, explosives, and fire-resistant materials.

Magnesium, as a supplement in feed processing, plays a crucial role in the material metabolism within livestock and poultry.

### Other Features * **Safety**: Magnesium sulfate heptahydrate is non-flammable

* **Preparation Method**: It can be prepared through various methods, such as recrystallization after adding sulfuric acid to natural magnesium carbonate (dolomite), or extraction from seawater, etc.

Summarily, Magnesium sulfate heptahydrate plays a significant role in various fields due to its unique chemical and physical properties, as well as its wide range of applications.