Which of the following compounds undergoes thermal decomposition to produce calcium oxide and carbon dioxide?

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RRB Technician Grade III Official Paper (Held On: 28 Dec, 2024 Shift 2)
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  1. Calcium chloride
  2. Calcium nitrate
  3. Calcium sulphate
  4. Calcium carbonate

Answer (Detailed Solution Below)

Option 4 : Calcium carbonate
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Detailed Solution

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The correct answer is Calcium Carbonate.

Key Points

  • Calcium carbonate (CaCO3) decomposes upon heating to produce calcium oxide (CaO) and carbon dioxide (CO2).
  • The thermal decomposition reaction of calcium carbonate is: CaCO3 (s) → CaO (s) + CO2 (g).
  • This decomposition occurs at a temperature of about 825°C (1517°F).
  • Calcium oxide (CaO), also known as quicklime, is widely used in construction and industrial processes.

Additional Information

  • Thermal Decomposition:
    • It is a chemical reaction where a compound breaks down into simpler compounds or elements upon heating.
    • Thermal decomposition reactions are usually endothermic, meaning they absorb heat.
  • Calcium Oxide (CaO):
    • Also known as quicklime or burnt lime.
    • Used in the manufacture of cement, steel, and paper, and in water treatment.
  • Carbon Dioxide (CO2):
    • A colorless, odorless gas that is a byproduct of the respiration of living organisms and the combustion of fossil fuels.
    • It is used in the production of carbonated beverages, as a refrigerant, and in fire extinguishers.
  • Other Thermal Decomposition Examples:
    • Calcium nitrate (Ca(NO3)2) decomposes to calcium oxide (CaO), nitrogen dioxide (NO2), and oxygen (O2).
    • Calcium sulfate (CaSO4) decomposes to calcium oxide (CaO) and sulfur trioxide (SO3).
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