Question

A metal compound ‘X’ reacts with dil.H₂SO₄ to produce effervescence. The gas evolved extinguishes a burning candle. If one of the compounds formed is calcium sulphate, then what is ‘X’ and the gas evolved? Also, write a balanced chemical equation for the reaction which occurred.

Answer 1

Given that the metal compound ‘X’ reacts with dil.H2SO4 to produce effervescence and the gas evolved extinguishes a burning candle. Now, since the gas evolved extinguishes the candle it must be carbon dioxide. It is also given that one of the compounds formed is calcium sulphate, hence the metal compound X is calcium carbonate. 

Hence, the reaction between calcium carbonate and dil.H₂SO₄ is as follows: - 

CaCO₃ + H₂SO₄→ CaSO₄ + CO₂ + H₂O