Question

give reason: particles of potassium permangananate spread easily in water kept at room temperature but not in very cold water

Answer 1

as kinetic energy increases with increase in temperature i.e. it will travel faster in hotter objects .particles of potassium per manganate spread easily in water kept at room temperature as the temperature of water of room temperature is high as compared to cold water..
HOPE IT HELPS! !

Answer 2

First of all the the process which makes the potassium permanganate or any other dyes is by diffusion.
Diffusion is the movement of molecules from higher concentration to the lower concentration.

molecule of gas have a lots of energy spread out even more than the molecules of liquid. warm water has more energy than cold water which means that molecules in warm water move faster than molecules in cold water.
hence, it spreads easily.