Question

Three mixtures A, B and C are obtained by stirring three different solids in water taken in separate beakers. When mixture A is allowed to stand for some time, then its particles settle at the bottom of the beaker. When a beam of light is passed through mixture A in a dark room, the path of light becomes visible when observed from the side of the beaker. When mixture B is allowed to stand for a considerable time, even then its particles do not settle down. Mixture B, however, scatters the beam of light just like mixture A. The particles of mixture C do not settle down on keeping and it also does not scatter a beam of light passing through it.

What are the mixtures like A known as ?

What are the mixtures like B known as ?

What are the mixtures like C known as ?

Name the phenomenon exhibited by A and B which occurs on passing a beam of light through them.

Name one mixture each which is like (i) A (ii) B, and (iii) C.

Answer 1

1. Mixtures like A are known as suspensions.
2. Mixtures like B are known as colloids.
3. Mixtures like C are known as true solutions.
4. The phenomenon exhibited by A and B, which occur on passing a beam of light through them, is called Tyndall effect.   
5. i. Mud water mixture is like A.
   ii.Soap solution is a mixture like B.
   iii. Sugar solution is a mixture like C.