Question

What happens when bar magnet moved over the two containers, one centaining trees
sulphur; and other containing iron sulphide? Explain with reason​

Answer 1

Q11) 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.

Solution:

Physical change:

The properties of iron and sulphur do not change when they are separated.

There is no formation of a new product in this change.

There is no change in the heat energy level of the mixture.

The change is temporary and reversible as iron and sulphur can be mixed again.

Chemical Change:

There are changes in properties of both on heating, they lose their magnetic power.

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.

The change is permanent, which means it cannot be reversed.