Question

Zig-zag motion of the solute particle in a solution is known as:
A. Linear motion
B. Linear motion
C. Circular motion
D. Curved motion

Answer 1

Hint: When we see a colloidal solution under an ultra microscope, the colloidal particles can be seen constantly moving in a zigzag path. The property was discovered by Robert Brown in 1827, when he observed that pollen grains suspended in water displayed random zigzag motion.

Complete step by step answer: We know that the colloidal particles present in a colloidal solution show a significant property known as Brownian movement. We can define Brownian movement as the uninterrupted zigzag movement of the colloidal particles in the dispersion medium in a colloidal solution.
We can say Brownian movement is because of the unequal bombardment of the moving molecules of dispersion medium on colloidal particles. The moving molecules of the dispersion medium endlessly hit on colloidal particles from all sides and pass on momentum to them.
Since their collisions are unequal, the net driving force present on a colloidal particle forces it to move about a particular direction. As the particle moves in that direction, other molecules of the medium again collide with it and the direction of the particle is changed. The process goes on and leads to a random zigzag movement of the colloidal particle.
Therefore, the option (B) is correct.

Note: We have to know there is a decrease in Brownian movement with an increase in the colloidal particle size. This is the reason why suspensions do not show this kind of movement. We remember that the Brownian movement plays a vital role in imparting stability to a sol. This is because the Brownian movement opposes the gravitational forces that act on colloidal particles and prevent them from getting settled down.