Question

What is the chemical composition pearl?
1. Calcium carbonate
2. Calcium sulphate
3. Calcium carbide
4. Calcium chloride
5. None of the above/More than one of the above

Answer 1

Correct Answer - Option 1 : Calcium carbonate

The correct answer is Calcium carbonate.

• Calcium Carbonate is a chemical compound having the chemical formula CaCO3.
  • It is a white insoluble powder-like substance occurring naturally in minerals, chalk, marble, limestone, calcite, shells, pearl, etc.

• Gypsum is widely known as Calcium Sulphate Dihydrate. 
  • Gypsum is composed of Calcium Sulphate (CaSO4) and water (H2O) and its chemical name is Calcium Sulphate Dihydrate (CaSO4.2H2O).
  • It is mainly used as a fertilizer and as the main ingredient in many forms of plaster, toy, blackboard chalk and drywall.
• Calcium carbide (CaC₂) is a solid chemical compound of dark grey colour.
  • It is brittle and insoluble in kerosene
  • If it comes into contact with water, it produces acetylene gas.
• Calcium chloride (CaCl2): It is an admixture of an accelerator category. These kinds of admixtures accelerate the hydration reactions in concrete and increase the rate of strength gain. Thus, CaCl2 is the prime additional constituent of rapid hardening cement.