The key difference between calcium chloride and magnesium chloride is that the calcium chloride contains a calcium cation with two chloride anions whereas the magnesium chloride contains a magnesium cation with two chloride anions.
Both calcium chloride and magnesium chloride are salt compounds containing cations and anions. These are solids at room temperature that are highly soluble in water. Moreover, both of these are used for dust control. Let us talk more details about them.
CONTENTS
1. Overview and Key Difference
2. What is Calcium Chloride
3. What is Magnesium Chloride
4. Side by Side Comparison – Calcium Chloride vs Magnesium Chloride in Tabular Form
5. Summary
What is Calcium Chloride?
Calcium chloride is an inorganic salt having a calcium ion associated with two chloride ions. The chemical formula of this compound is CaCl2. The molar mass is 110.9 g/mol. At room temperature, it exists as a crystalline white solid. Moreover, it is hygroscopic and readily dissolves in water. Therefore we can use it as a desiccant. It is available as either the anhydrous form or hydrated forms. The melting and boiling points of the anhydrous calcium chloride are 775 °C and 1,935 °C respectively. The major method of producing calcium chloride is as a byproduct of the Solvay process. It uses limestone.
2 NaCl + CaCO3 → Na2CO3 + CaCl2
One of the major applications of this compound is as a de-icing agent. It de-ices by the depressing freezing point of water.
Figure 01: Calcium Chloride Crystals
The second largest application is that it is used as a dust controlling agent. Due to its hygroscopic properties, a concentrated solution can keep a liquid layer on the dirt of the surface of a road. Hence it controls the dust. Moreover, it can increase the water hardness. Ex: to increase the hardness of water in swimming pools.
What is Magnesium Chloride?
Magnesium chloride is an inorganic salt having a magnesium ion associated with two chloride ions. The chemical formula of this compound is MgCl2. The molar mass is 95 g/mol. The melting point and boiling points are 714 °C and 1,412 °C respectively. At room temperature, it exists as a white or colorless crystalline solid. It is highly water soluble and is available in hydrated forms as well. We can extract the hydrate form from brine or sea water. There are several hydrates of this compound which contain 2, 4, 6, 8 or 12 water molecules. These hydrates lose these water molecules upon heating. We can produce this compound via the Dow process. There, magnesium chloride regenerates from magnesium hydroxide upon the reaction with hydrochloric acid.
Mg(OH)2(s) + 2 HCl → MgCl2(aq) + 2 H2O(l)
A major application of anhydrous magnesium chloride is that it is useful as a precursor to produce magnesium metal.
Figure 02: Magnesium Chloride Crystals
We can produce this metal via electrolysis of MgCl2. Moreover, we can use this compound for dust controlling, solid stabilization, wind erosion mitigation, etc. As another importance, we use MgCl2 as a catalyst support for Ziegler-Natta catalyst.
What is the Difference Between Calcium Chloride and Magnesium Chloride?
Calcium chloride is an inorganic salt having a calcium ion associated with two chloride ions. Therefore ,the chemical formula of this compound is CaCl2. Its molar mass is 110.9 g/mol. Moreover, the melting and boiling points of the anhydrous calcium chloride are 775 °C and 1,935 °C respectively. Magnesium chloride is an inorganic salt having a magnesium ion associated with two chloride ions. Therefore the chemical formula of this compound is MgCl2. Its molar mass is 95 g/mol. In addition to that, the melting point and boiling point of the anhydrous magnesium chloride are 714 °C and 1,412 °C respectively. These compounds have different applications, but one in common; both of them are important dust controlling agents.
Summary – Calcium Chloride vs Magnesium Chloride
Both calcium and magnesium chloride are important as dust control agents. The difference between calcium chloride and magnesium chloride is that the calcium chloride contains a calcium cation with two chloride anions whereas the magnesium chloride contains a magnesium cation with two chloride anions.
Reference:
1. “Calcium Chloride.” Wikipedia, Wikimedia Foundation, 23 July 2018. Available here
2. “Magnesium Chloride.” National Center for Biotechnology Information. PubChem Compound Database, U.S. National Library of Medicine. Available here
Image Courtesy:
1.’Calcium chloride CaCl2’By No machine-readable author provided. (CC BY-SA 3.0) via Commons Wikimedia
2.’Magnesium chloride’ (Public Domain) via Commons Wikimedia