Question

Which of the following is not colloid?
A) Muddy water
B) Blood
C) Milk
D) None of the above

Answer 1

Colloids are heterogeneous mixtures in which one phase is dispersed uniformly in another phase. Heterogeneous mixtures are of two types-colloid and suspension.

Complete answer:
In the question, few options are given and we have to say which one among them is not a colloidal solution.
So we have to know about the different classification of mixtures-
There are mainly two classification-Homogeneous mixture and heterogeneous mixture.
The homogeneous mixture is the mixture in which composition will be the same for every sample of the mixture and it is mainly called as the solutions or true solutions.
True solutions are those in which the solute particles completely dissolve in the solvent and form mixtures which have the same composition and are called a solution.
Example-salt solution
Heterogeneous mixture –these are mixtures with non-uniform composition. And they are classified into two types.
They are colloids and suspensions.
Both are heterogeneous mixtures, but they differ by a few points.
The particle size in suspension is greater than that of a colloidal solution.
In colloids the soluble or insoluble dispersed particles are distributed uniformly in the dispersion medium whereas in suspension the particles are not soluble and they settle down when they are kept undisturbed.
As the particle size, dispersed in the dispersion medium in the suspension is greater they settle down easily whereas, no such phenomenon is possible in colloids.
Now let’s consider the options given.
-Muddy water comes under the classification of suspension as the dispersed particle is not soluble in the dispersion medium and settles down when they are left undisturbed.
-Blood comes under the classification of colloid.
-Milk is also a colloid.
So we can conclude that, since muddy water is a suspension and it is not a colloid.

So the correct answer for the option is option (A).

Note: The particle size of the dispersed particles which is spread uniformly in the dispersion medium is having a particle size of greater than a true solution but less than that of a suspension. The dispersed particles in the colloidal solution cannot be separated using filtration techniques. If a question is asked, which solution will show the Tyndall effect, a light scattering phenomenon, then we should opt for a colloidal solution. Since colloidal solutions show this phenomenon.