Question

If for liquid in a vessel, the force of cohesion is twice of the force of adhesion, then
A. The liquid will wet the solid.
B. The liquid will not wet the solid.
C. The meniscus will be convex upwards.
D. The angle of contact will be obtuse.

Answer 1

Hint: Force of adhesion known as the bonding between the molecules of the liquid. We say that the force of adhesive refers to the unlike substance which means it is sticking together. It is caused due to the attraction of opposing forces. But from the question, we know that the force of cohesion is twice the force of adhesion. So there is the attraction of the force twice between the forces.

Complete step by step answer:
Adhesive forces are due to the attraction of two or more different molecules. Adhesive and cohesive forces are different in their strengths. But cohesive force is caused only in the two similar substances. Adhesive force is caused due to the force of attraction between the molecules and the xylem vessels. It is mainly caused due to the electrostatic or mechanical force between the two different substances.
The curved surface is formed due to the effect of the adhesion force. Capillary action is the effect of cohesive force.
If the cohesive forces become moved, then the liquid will not stick to the walls of the container because of their strong bonding. So the meniscus will be the convex upwards it is resulting in the angle more than. So, the strong adhesive force is caused by the liquid and the surface.

Hence option C is the correct option.

Note:
Cohesive force occurs only in similar substances. But adhesive force occurs only in the different substances. The curved surface is formed due to the effect of the adhesion force. capillary action is the effect of cohesive force.