Chemistry
Give reasons why - separation of mixtures e.g., iron from a mixture of iron and sulphur is a physical change, but heating a mixture of iron and sulphur is considered a chemical change.
Phy & Chem Changes
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Answer
As separation of iron and sulphur from its mixture is a
- reversible process,
- no new products are formed and
- mixture has the same properties as iron and sulphur individually have. Hence, it is a physical change.
However, on heating of iron and sulphur,
- a new product iron sulphide is formed
- this new product [iron sulphide] has completely different properties from iron and sulphur.
- it is an irreversible process. Hence, it is a chemical change.
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