Q. Pick out the statement which is not relevant in the discussion of colloids.
A) Sodium aluminium silicate is used in the softening of hard water
B) Potash alum is used in shaving rounds and as a styptic in medicine
C) Artificial rain is caused by throwing electrified sand on the clouds from an aeroplane
D) Deltas are formed at place where the river pours its water into the sea
Explanation
(a)
The action of sodium aluminium silicate(zeolite) on hard water is not an example of colloidal action. It is actually the simple chemical substitution of calcium salts with zeolite so that calcium zeolite precipitates out, and hardness of water removes.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.