Question

Please answer these questions

Answer 1

Answer- The above question is from the chapter 'Chemical Reactions and Equations'.

Q6.) Mention atleast 3 basic characteristic features to prove that a chemical reaction has taken place.

Answer: 3 basic characteristic features to prove that a chemical reaction has taken place are:

1. Evolution of heat and light

2. Change of colour

3. Evolution of gas

Q7.) Kusum took a pale green substance A in a test tube and heated it over the flame of a burner. A brown colour residue B was formed along with evolution of two gases with burning smell of sulphur. Identify A and B and write the chemical reactions involved.

Answer: A = Hydrated Ferrous Sulphate (FeSO₄.7H₂O)

B = Ferric Oxide (Fe₂O₃)

The required chemical equations are:

                           Δ

1) FeSO₄.7H₂O ------> FeSO₄ + 7H₂O

                    Δ

2) 2FeSO₄ -------> Fe₂O₃ + SO₂ + SO₃