Calcium Chloride vs. Calcium Dihydrate

Attribute	Calcium Chloride	Calcium Dihydrate
Chemical Formula	CaCl2	CaCl2•2H2O
Molar Mass	110.98 g/mol	147.01 g/mol
Appearance	White deliquescent solid	White solid
Solubility	Highly soluble in water	Soluble in water
Uses	De-icing agent, food additive, desiccant	Food additive, drying agent

Introduction

Calcium chloride and calcium dihydrate are two common forms of calcium salts that are used for various purposes. While both compounds contain calcium, they have different chemical compositions and properties that make them suitable for different applications. In this article, we will compare the attributes of calcium chloride and calcium dihydrate to understand their differences and similarities.

Chemical Composition

Calcium chloride is a salt composed of calcium and chlorine ions. Its chemical formula is CaCl2, indicating that it contains one calcium ion for every two chloride ions. On the other hand, calcium dihydrate is a hydrated form of calcium chloride, with the chemical formula CaCl2·2H2O. This means that calcium dihydrate contains two molecules of water for every molecule of calcium chloride. The presence of water molecules in calcium dihydrate affects its properties compared to anhydrous calcium chloride.

Solubility

One of the key differences between calcium chloride and calcium dihydrate is their solubility in water. Calcium chloride is highly soluble in water, with a solubility of about 74 grams per 100 milliliters of water at room temperature. This high solubility makes calcium chloride a popular choice for de-icing roads and sidewalks in winter. On the other hand, calcium dihydrate is less soluble in water compared to anhydrous calcium chloride. The presence of water molecules in calcium dihydrate reduces its solubility in water, making it less effective for de-icing purposes.

Hygroscopicity

Another important property to consider when comparing calcium chloride and calcium dihydrate is their hygroscopicity. Calcium chloride is known for its hygroscopic nature, meaning it has the ability to absorb moisture from the air. This property makes calcium chloride useful as a desiccant for drying gases and controlling humidity in various applications. On the other hand, calcium dihydrate is less hygroscopic compared to anhydrous calcium chloride due to the presence of water molecules in its structure. This makes calcium dihydrate less effective as a desiccant compared to calcium chloride.

Uses

Both calcium chloride and calcium dihydrate have various industrial and commercial uses due to their unique properties. Calcium chloride is commonly used as a de-icing agent for roads and sidewalks in winter, as well as a desiccant for drying gases and controlling humidity. It is also used in food preservation, wastewater treatment, and as a source of calcium in food supplements. On the other hand, calcium dihydrate is used in the production of calcium salts, as a drying agent in the laboratory, and as a source of calcium in food and beverages. The hydrated form of calcium chloride, calcium dihydrate, is also used in pharmaceuticals and cosmetics.

Toxicity

When comparing calcium chloride and calcium dihydrate, it is important to consider their toxicity levels. Calcium chloride is considered safe for use in food and pharmaceutical applications when used in appropriate amounts. However, excessive consumption of calcium chloride can lead to hypercalcemia, a condition characterized by high levels of calcium in the blood. On the other hand, calcium dihydrate is also safe for use in food and pharmaceutical applications, but excessive consumption can lead to similar health risks as calcium chloride. It is important to follow recommended dosage guidelines when using calcium salts to avoid potential health issues.

Conclusion

In conclusion, calcium chloride and calcium dihydrate are two common forms of calcium salts that have distinct properties and uses. While calcium chloride is highly soluble and hygroscopic, calcium dihydrate is less soluble and hygroscopic due to the presence of water molecules in its structure. Both compounds have various industrial and commercial applications, ranging from de-icing roads to food preservation. It is important to consider the specific properties and uses of calcium chloride and calcium dihydrate when choosing the appropriate compound for a particular application.