Grade 11 → S-block elements (alkali and alkaline earth metals) ↓
Important Compounds of Magnesium and Calcium
The elements magnesium and calcium belong to the group of s-block elements known as alkaline earth metals. These elements form various compounds that are essential in both biological and industrial contexts. In this exploration, we will delve deep into some of the most important compounds of these two elements, their properties, preparation, and applications.
Magnesium compounds
1. Magnesium oxide (MgO)
Magnesium oxide, also known as magnesia, is a white hygroscopic solid mineral. Its chemical formula is MgO
and it is produced by burning magnesium in the presence of oxygen or by the thermal decomposition of magnesium carbonate.
2Mg + O2 → 2MgO
Property:
- white powder
- High melting point about 2852°C
- Refractory material, which means it can withstand high temperatures
Use:
- Used as refractory material in furnace lining.
- Acts as an insulator in industrial applications.
- In medical applications it is used as an antacid to relieve stomach irritation and indigestion.
2. Magnesium hydroxide (Mg(OH)2)
Commonly known as milk of magnesia, this compound is often used as an antacid or laxative. Its chemical formula is Mg(OH)2
.
MgO + H2O → Mg(OH) 2
Property:
- white, slightly soluble solid
- forms a gelatinous suspension when dissolved in water
Use:
- As an antacid, it treats stomach acidity problems.
- Used as a laxative to relieve constipation.
- Acts as a fire retardant and food additive.
3. Magnesium sulphate (MgSO4)
Magnesium sulfate is commonly known as Epsom salt. It is often found as the heptahydrate sulfate mineral epsomite (MgSO4·7H2O
).
Mg + H 2 SO 4 → MgSO 4 + H 2
Property:
- Colorless crystalline solid
- Highly soluble in water
Use:
- It is used in therapeutic baths as it relaxes the muscles.
- Enhances the taste of some beverages such as mineral water.
- Used as a drying agent in chemical laboratories.
Calcium compounds
1. Calcium oxide (CaO)
Calcium oxide, also known as quicklime, is obtained from the thermal decomposition of calcium carbonate. It is a white, caustic, alkaline crystalline solid at room temperature.
CaCO 3 → CaO + CO 2 (Heat)
Property:
- White, alkaline, crystalline solid
- High melting point about 2572°C
Use:
- Used in the production of glass, cement and iron.
- Used in agriculture to treat acidic soils.
- Due to its moisture-absorbing properties it acts as an absorbent.
2. Calcium hydroxide (Ca(OH)2)
Also called slaked lime, calcium hydroxide is made by mixing calcium oxide with water. It has many applications due to its strong alkaline properties.
CaO + H 2 O → Ca(OH) 2
Property:
- white powder
- Partially soluble in water, forms calcium hydroxide, commonly known as lime water
Use:
- Used to neutralize acidic soil.
- Used in water treatment to remove impurities.
- Essential in the pulp making process in the paper industry.
3. Calcium carbonate (CaCO3)
Calcium carbonate is found in nature in the form of limestone, marble and chalk. Due to its properties, it is extensively used in industries and academia.
Ca(OH) 2 + CO 2 → CaCO 3 + H 2 O
Property:
- white, insoluble solid
- Stable compound that does not decompose easily at ambient temperature
Use:
- Used in the construction industry as a building material.
- Functions as a dietary calcium supplement in health care.
- Acts as a filler in the production of paints, paper and rubber.
Conclusion
Magnesium and calcium compounds have diverse and wide applications that span across many sectors including industrial processes, healthcare, agriculture, and construction. Understanding their unique properties and uses helps us appreciate their importance in everyday life. These compounds not only support vital physiological processes but also contribute significantly to various technological and commercial advancements.
From the soothing effect of Epsom salt baths to the structural strength provided by calcium carbonate in construction, magnesium and calcium compounds surround us in many ways, often without our explicit awareness. Through their versatile utility, they undeniably hold a vital place within both natural ecosystems and human industries.