The key difference between CoCl2 6H2O and anhydrous cobalt chloride is that the CoCl2 6H2O crystals have water of crystallization whereas the anhydrous cobalt chloride has no water of crystallization. Furthermore, the visually identifiable difference between CoCl2 6H2O and anhydrous cobalt chloride is that the CoCl2 6H2O is rose-red in color while the anhydrous cobalt chloride is sky-blue in color.
Cobalt chloride is a salt of cobalt. Moreover, it is an inorganic compound having the chemical formula CoCl2. The hydrated form of this compound is a hexahydrate compound that has one cobalt chloride salt molecule attracted to six water molecules.
CONTENTS
1. Overview and Key Difference
2. What is CoCl2 6H2O
3. What is Anhydrous Cobalt Chloride
4. Side by Side Comparison – CoCl2 6H2O vs Anhydrous Cobalt Chloride in Tabular Form
5. Summary
What is CoCl2 6H2O?
CoCl2 6H2O is cobalt chloride hexahydrate that has cobalt chloride slat molecules attracted with six water molecules. this hydrated form has a rose red color and it is a crystalline compound. The molar mass of this compound is 237.93 g/mol. Its density is about 1.924 g/cm3.
Figure 01: Hydrated Cobalt Chloride
The melting point of this compound is 86◦C. This hydrated form has an octahedral geometry. This compound is deliquescent. Upon heating, CoCl2 6H2O dehydrates by evaporating water molecules.
What is Anhydrous Cobalt Chloride?
Anhydrous cobalt chloride is the water-free from of cobalt chloride salt. It has no water of crystallization. It has a sky blue color. The molar mass of this compound is 129.84 g/mol. The melting point is 735◦C. The compound has a hexagonal geometry.
Figure 02: Anhydrous Cobalt Chloride
In addition, it is a hygroscopic compound. This compound can act as a desiccant because it can absorb water molecules.
What is the Difference Between CoCl2 6H2O and Anhydrous Cobalt Chloride?
CoCl2 6H2O is cobalt chloride hexahydrate that has cobalt chloride slat molecules attracted with six water molecules. It has a rose-red color. The molar mass of this compound is high due to the presence of water molecules. Moreover, it converts into the anhydrous form upon heating. Anhydrous cobalt chloride is the water-free from of cobalt chloride salt. It has a sky blue color. In addition, it acts as a desiccant because it can absorb water.
Summary – CoCl2 6H2O vs Anhydrous Cobalt Chloride
Cobalt chloride is a common salt that we use in laboratories as a source of cobalt. It is available in the anhydrous form, dehydrated form and hexahydrate form. The difference between CoCl2 6H2O and anhydrous cobalt chloride is that the CoCl2 6H2O crystals have water of crystallization whereas anhydrous cobalt chloride has no water of crystallization.
Reference:
1. “Cobalt(II) Chloride.” Wikipedia, Wikimedia Foundation, 13 June 2018. Available here
Image Courtesy:
1.’Cobalt(II) chloride hexahydrate sample’By Leiem – Own work, (CC BY-SA 4.0) via Commons Wikimedia
2.’Anhydrous Cobalt(II)-chloride’By Softyx – Own work, (CC BY-SA 3.0) via Commons Wikimedia