EVERYDAY SCIENCE

Detailed explanation-1: -The equation for the reaction that produces the iron sulfide is: Fe + S → FeS (heat) Page 2 Maine Geological Survey | 2 One atom of iron (or a million atoms of iron) and one atom of sulfur (or one million atoms of sulfur) react with heat to make one molecule of iron sulfide (or a million molecules of iron sulfide).

Detailed explanation-2: -But in case of heating of iron and sulphur, a new product iron sulphide is formed. This new product iron sulphide have completely differ property from iron and sulphur, hence it is a chemical change.

Detailed explanation-3: -Chemical Change: A new substance, iron sulphide is formed. The heat energy is released when the iron and sulphur mixture is heated. The test tube becomes red hot.

Detailed explanation-4: -But when iron filings and sulphur powder are mixed and heated they undergo chemical reactions leading to the formation of ferrous sulphide. So, heating of the mixture of iron filing and sulphur powder is regarded as a chemical change.

Detailed explanation-5: -When iron filling and sulphur powder are mixed and heated they undergo a chemical reaction and form ferrous sulphide (FeS). It is a new substance which has properties entirely different from Fe and S. Therefore, heating of mixture of iron and sulphur powder is a chemical change.