Magnesium Chloride vs. Magnesium Chloride Hexahydrate

Attribute	Magnesium Chloride	Magnesium Chloride Hexahydrate
Chemical Formula	MgCl2	MgCl2•6H2O
Molar Mass	95.211 g/mol	203.31 g/mol
Appearance	White crystalline solid	White crystalline solid
Solubility	Soluble in water	Soluble in water
Hydrate	Anhydrous	Hexahydrate

Introduction

Magnesium chloride and magnesium chloride hexahydrate are two common forms of magnesium salts that are used for various purposes. While they both contain magnesium and chloride ions, there are some key differences between the two compounds that make them unique in their own ways. In this article, we will compare the attributes of magnesium chloride and magnesium chloride hexahydrate to help you understand their differences and similarities.

Chemical Composition

Magnesium chloride, also known as MgCl2, is a simple inorganic compound that consists of one magnesium ion (Mg2+) and two chloride ions (Cl-) per molecule. On the other hand, magnesium chloride hexahydrate, also known as MgCl2·6H2O, contains one magnesium ion, two chloride ions, and six water molecules per molecule. This means that magnesium chloride hexahydrate has a higher water content compared to magnesium chloride.

Solubility

One of the key differences between magnesium chloride and magnesium chloride hexahydrate is their solubility in water. Magnesium chloride is highly soluble in water, meaning that it can easily dissolve and form a clear solution. On the other hand, magnesium chloride hexahydrate is less soluble in water compared to magnesium chloride. This difference in solubility can affect the way these compounds are used in various applications.

Hygroscopicity

Another important attribute to consider when comparing magnesium chloride and magnesium chloride hexahydrate is their hygroscopicity. Magnesium chloride hexahydrate is known to be more hygroscopic compared to magnesium chloride. This means that magnesium chloride hexahydrate has a greater tendency to absorb moisture from the surrounding environment, leading to the formation of hydrated crystals. On the other hand, magnesium chloride is less hygroscopic and tends to remain in its anhydrous form under normal conditions.

Uses

Both magnesium chloride and magnesium chloride hexahydrate have various uses in different industries. Magnesium chloride is commonly used as a de-icing agent for roads and sidewalks during winter months. It is also used in the production of magnesium metal, as a catalyst in chemical reactions, and as a nutritional supplement for magnesium deficiency. On the other hand, magnesium chloride hexahydrate is often used in the preparation of magnesium salts for pharmaceutical and medical applications. It is also used in the production of magnesium hydroxide for wastewater treatment and as a desiccant in laboratories.

Physical Properties

When it comes to physical properties, magnesium chloride and magnesium chloride hexahydrate exhibit some differences. Magnesium chloride is a white crystalline solid at room temperature with a melting point of 714°C. It has a density of 2.32 g/cm3 and is odorless. On the other hand, magnesium chloride hexahydrate appears as colorless crystals with a melting point of 117°C. It has a density of 1.569 g/cm3 and is also odorless. These differences in physical properties can impact the handling and storage of these compounds.

Toxicity

Both magnesium chloride and magnesium chloride hexahydrate are considered to be relatively safe compounds when handled properly. However, it is important to note that excessive exposure to magnesium chloride can lead to skin irritation and respiratory issues. Ingesting large amounts of magnesium chloride can also cause gastrointestinal disturbances. Similarly, magnesium chloride hexahydrate can cause skin irritation and eye irritation upon contact. Ingesting magnesium chloride hexahydrate in large quantities can lead to gastrointestinal issues as well. It is important to follow proper safety precautions when working with these compounds.

Conclusion

In conclusion, magnesium chloride and magnesium chloride hexahydrate are two distinct compounds with their own unique attributes. While both compounds contain magnesium and chloride ions, they differ in terms of chemical composition, solubility, hygroscopicity, uses, physical properties, and toxicity. Understanding these differences can help in choosing the right compound for specific applications. Whether you are looking to de-ice roads, produce magnesium metal, or prepare pharmaceuticals, knowing the characteristics of magnesium chloride and magnesium chloride hexahydrate is essential for successful outcomes.