The molecular formula for calcium chloride hydrate, specifically calcium chloride dihydrate, is H4CaCl2O2. This formula is equivalent to the more commonly represented chemical formula CaCl2·2H2O, which indicates that two molecules of water are associated with each unit of calcium chloride.
Key Chemical Identifiers for Calcium Chloride Dihydrate
Calcium chloride dihydrate possesses distinct chemical properties and identifiers, as detailed below:
| Property | Value |
|---|---|
| Molecular Formula | H4CaCl2O2 |
| Average Mass | 147.008 g/mol |
| Monoisotopic Mass | 145.921426 g/mol |
| ChemSpider ID | 23227 |
Understanding Calcium Chloride Hydrates
Calcium chloride is a salt known for its strong hygroscopic nature, meaning it readily absorbs moisture from the atmosphere. When it absorbs water, it forms various crystalline structures known as hydrates. These hydrates contain water molecules incorporated into their crystal lattice.
Common forms of calcium chloride hydrates include:
- Calcium Chloride Dihydrate (CaCl2·2H2O or H4CaCl2O2): This is one of the most prevalent forms, often found as a white, crystalline solid.
- Calcium Chloride Hexahydrate (CaCl2·6H2O): This form contains six water molecules per calcium chloride unit.
- Anhydrous Calcium Chloride (CaCl2): This form contains no water molecules and is highly effective as a desiccant due to its intense affinity for water.
Properties and Practical Applications
Calcium chloride hydrates, particularly the dihydrate, are widely used across various industries due to their unique properties:
- Hygroscopicity: Their strong ability to absorb moisture makes them excellent desiccants.
- Exothermic Reaction with Water: When dissolved in water, calcium chloride releases heat, which is useful in many applications.
- Lowers Freezing Point: Calcium chloride significantly lowers the freezing point of water.
Some key applications include:
- De-icing and Snow Removal: Commonly used on roads and sidewalks to melt ice and prevent freezing, offering better performance at lower temperatures compared to some other salts.
- Desiccant and Drying Agent: Utilized in industrial processes, laboratories, and moisture absorbers for homes to remove humidity and dry gases or liquids.
- Food Additive: Approved as a firming agent in canned vegetables, a preservative, and an electrolyte in sports beverages. It also plays a role in cheesemaking.
- Dust Control: Applied to unpaved roads to attract moisture, which helps bind dust particles and stabilize the road surface.
- Brine Refrigeration: Used as a brine solution in refrigeration plants due to its low freezing point.
Safety and Handling
While widely used, calcium chloride should be handled with care. It can cause skin and eye irritation and is exothermic when it dissolves in water, meaning it releases heat that can be significant. Always follow safety guidelines and use appropriate personal protective equipment when handling this chemical.
