Question

Dipti was asked to prepare four separate mixtures in four beakers A, B, C and D by mixing sugar, fine sand and thin paste of starch and chalk powder respectively in water and then categorise each as stable or unstable. What will be correct categorization?

Answer 1

A stable mixture is defined as a mixture in which solute particles do not settle, that is, in a stable mixture the particles remain individual. Whereas an unstable mixture is defined as a mixture in which solute particles settle or coagulate into the solvent.

Complete answer:
A mixture is defined as a substance in which two or more solutes are added. Particles of a mixture never combine chemically with each other. We define stable mixture as a mixture in which solute particles do not settle. Basically, in a stable mixture particles remain individual. For example, salt in water is a stable mixture.
On the other hand, an unstable mixture is defined as a mixture in which solute particles settle or coagulate into the solvent.
For example, mud in water is an unstable mixture.
So, given in the question are separate mixtures in four beakers A, B, C and D by mixing sugar, fine sand and thin paste of starch and chalk powder respectively in water.
Mixture of sugar in water – Beaker A - Stable
Mixture of fine sand in water - Beaker B - unstable
Mixture of thin paste of starch in water - Beaker C- stable
Mixture of chalk powder in water - Beaker D-unstable

Note: In chemistry, a mixture is a material which is made up of two or more different substances that are physically combined. It is the physical combination of two or more substances in which the identities are retained and are mixed in the form of solutions, suspensions and colloids.