Question

Bhavna took a pale green substance A in a test tube and heated over the flame of a burner a brown colour Residue B was formed along with the evolution of two gases burning smell of sulphur identify the elements A and B and name the chemical reaction​

Answer 1

Answer:

Ferrous sulphate(FeSO₄) is green in colour.

When heated , it decomposes to form ferric oxide (Fe₂O₃) , which is reddish brown in colour , and two gases , namely , Sulphur dioxide (SO₂) and Sulphur trioxide (SO₃) are evolved.

                heat

2FeSO₄ ------------> Fe₂O₃ + SO₂ + SO₃ .

This reaction is and example of decompostion reaction .

As this reaction needs heat to take place , this reaction is categorized as thermal decomposition reaction.

The burning smell of sulphur is obtained as sulphur dioxide gase and trioxide gas evolved.