Question

Distinguish between true solution and colloidal solution.

Answer 1

Hint: We can recall that the solution of sugar in water is homogeneous but milk is not. When we closely look at milk we can see oil droplets floating in it. Thus, although it appears to be homogeneous it is actually heterogeneous in nature. The nature of the solution formed depends upon the size of the solute particles and this is how we can distinguish true and colloidal solution.

Complete step by step solution:
As per the heat, we can distinguish true and colloidal solutions on the basis of the size of the solute particles. If the size of the solute particles is less than 1 nm it will form a true solution but when the size is between 1 to 100 nm then it will form a colloidal solution. When the size of solute particles is greater than 100 nm it will form a suspension. Therefore, we can conclude that colloidal is an intermediate state between true solution and suspension.
Some important properties of true solution and colloids are given in the table.

S.No.	Name of the property	True Solution	Colloids Solution
1.	Size	Size of particles is less than 1nm	Size of the particles is between 1 nm an 100 nm
2.	Filterability	Pass through ordinary filter paper and through animal membrane	Pass through ordinary filter paper but not through animal membrane
3.	Settling	Particles do not settle down on keeping	Particles do not settle down on their own but can be made to settle down by centrifugation
4.	Diffusion	Diffuse quickly	Diffuse slowly

Note: Colloids solution is heterogeneous in nature and always consists of at least two phases: the dispersed phase and the dispersion medium.
Dispersed Phase-It is the substance present in small proportion and consists of particles of colloids size (1 to 100 nm).
Dispersion medium: It is the medium in which the colloids particles are dispersed.