Question

Rahul and Manvi, each was given a mixture of iron filings and sulphur powder. Rahul heated the mixture strongly and a new substance was formed. State the observation.

Answer 1

1. When iron filings and sulphur powder are mixed, both retain their properties. Hence, mixing of iron and sulphur is a physical change.
2. When iron filings and sulphur powder are mixed and heated they undergo a chemical reaction and ferrous sulphide (FeS) is formed which is a new substance with entirely different properties from Fe and S. Therefore, heating of a mixture of iron and sulphur powder is a chemical change.