Lime water turns milky when carbon dioxide is passed through it. It is due to the formation of:

The correct answer is Calcium Carbonate.

Key Points

•  Calcium Carbonate
  • A limestone is a form of calcium carbonate.
  • Other Different forms of calcium carbonate are Chalk and Marble.
  • Calcium carbonate is a chemical compound with the formula CaCO3.
  • It is a common substance found in rocks as the minerals calcite and aragonite (most notably as limestone, which is a type of sedimentary rock consisting mainly of calcite) and is the main component of eggshells, snail shells, sea shells, and pearls.

Additional Information

• Barium Carbonate
  • ​Barium Carbonate (BaCO3) is a chemical compound Barium and Carbonate ions are chemically united in a fixed proportion. ​
• Calcium oxide
  • ​Calcium oxide is the chemical name of CaO.
  • Calcium oxide (CaO) compound is used as a drying agent.
  • The drying agent is used to remove water from an organic compound.
  • Calcium oxide is used to dry ammonia gas.
  • When Limestone (CaCO3) is heated, it gives Calcium oxide.
  • CaCO3 → CaO + Co2
  • It is also known as quick lime.
  • It is used for manufacturing cement, paper, Caustic Soda, etc.
• Calcium Hydrogen Carbonate
  • Calcium bicarbonate is also known as Calcium Hydrogen Carbonate.
  • It has a chemical formula Ca(HCO3)2.
  • From the above formula, we can say calcium bicarbonate has 2 hydrogen atoms.