Question

For Brownian motion of particles of suspensions in liquid. Answer the following :

(a) What should be the typical size of suspended particles?

(b) Bombardments of the suspended particles by molecules of the liquid are random. We should then expect equal no. of molecules hitting a suspended particle from all directions. Why the net impact is not zero.

(c) Can the assembly of suspended particles is considered a ‘gas’ of ‘heavy molecules’? If so, what is the temperature of this gas if temperature of the liquids is T?

Answer 1

(a) 10^-6 m.

(b) The average number of molecules hit in different directions so their net impact is not zero.

(c) Yes, since the heavy gas is in thermal equilibrium with the liquid, its temperature is equal to the temperature of liquid, i.e., T.