Question

Ramesh mixed some iron filings with sulphur powder in a China dish. In another dish, he mixed iron filings and sulphur powder and heated the mixture. Which of his observations is not correct?

• A. Dish $X$ shows a physical change while dish $Y$ shows a chemical change.
• B. In dish $X$ sulphur powder and iron filings can be seen separately.
• C. In dish $Y$ a new substance is formed on heating the mixture.
• D. The change which has taken place in dish $Y$ is reversible.

Answer 1

The correct option is D The change which has taken place in dish $Y$ is reversible.

In dish $Y$ iron powder reacts with sulfur exothermically to form iron (II) sulfide. The chemical reaction occurs and it is irreversible and black iron sulfide is formed.