Difference Between Calcium Chloride and Calcium Chloride Dihydrate

The key difference between calcium chloride and calcium chloride dihydrate is that calcium chloride is anhydrous while calcium chloride dihydrate is a hydrated form of calcium chloride.

Calcium chloride is an inorganic compound. It generally occurs as a hydrated compound. This means calcium chloride molecules exist in association with water molecules. The most common hydrate is dihydrate.

CONTENTS

1. Overview and Key Difference
2. What is Calcium Chloride 
3. What is Calcium Chloride Dihydrate
4. Side by Side Comparison – Calcium Chloride vs Calcium Chloride Dihydrate in Tabular Form
5. Summary

What is Calcium Chloride?

Calcium chloride is an inorganic compound containing CaCl2. It is the chloride salt of calcium metal. Furthermore, this compound occurs as a white crystalline solid at room temperature. It is highly water-soluble. Moreover, it is highly hygroscopic. Therefore, we can use it as a desiccant. Calcium chloride usually exists in hydrated forms. i.e. CaCl2(H2O)x, where x = 0, 1, 2, 4, and 6. In its anhydrous form, the melting point can range from 772–775 °C.

Calcium chloride has the following uses:

  • As a deicing agent to prevent ice formation
  • To reduce dust on roads
  • As a food additive
  • As a desiccant and drying agent
  • Used in concrete mixtures for the acceleration of initial settling

Figure 01: Appearance of Calcium Chloride (Anhydrous)

However, this compound is hazardous because it is an irritant for skin. Moreover, the consumption of calcium chloride can lead to hypercalcemia. When considering the preparation, calcium chloride can be produced via the Solvay process; we can get this compound as a byproduct of this process. Furthermore, the major ingredient for the Solvay process is limestone.

What is Calcium Chloride Dihydrate?

Calcium chloride dihydrate is an inorganic hydrated compound which has the chemical formula CaCl2(H2O)2. The molar mass of this compound is 111.56 g/mol. When considering the structure of this compound, it has one calcium chloride molecule in association with two water molecules. The melting point of this compound is 175 °C and upon further heating, it decomposes. Moreover, this dihydrate form naturally occurs as the rare evaporate “sinjarite”.

What is the Difference Between Calcium Chloride and Calcium Chloride Dihydrate?

Calcium chloride is an inorganic compound containing CaCl2 while Calcium chloride dihydrate is an inorganic hydrated compound which has the chemical formula CaCl2(H2O)2. The key difference between calcium chloride and calcium chloride dihydrate is that calcium chloride is anhydrous while calcium chloride dihydrate is a hydrated form of calcium chloride. Furthermore, calcium chloride naturally occurs either as the rare evaporate “sinjarite” or as “antarcticite” while calcium chloride dihydrate occurs as sinjarite.

Summary – Calcium Chloride vs Calcium Chloride Dihydrate

Calcium chloride is an inorganic compound containing CaCl2 while Calcium chloride dihydrate is an inorganic hydrated compound which has the chemical formula CaCl2(H2O)2. The key difference between calcium chloride and calcium chloride dihydrate is that calcium chloride is anhydrous while calcium chloride dihydrate is a hydrated form of calcium chloride.