Question

Pls I need help urgently. In case of water, which effect, adhesion or cohesion is the strongest? Explain

Answer 1

In the case of water, cohesion is stronger than adhesion. Cohesion refers to the intermolecular forces that bind water molecules to each other, while adhesion refers to the intermolecular forces that bind water molecules to a surface or material.

Water molecules are strongly attracted to each other due to hydrogen bonding, which is a type of intermolecular force that occurs between a hydrogen atom of one water molecule and an oxygen atom of another water molecule. These hydrogen bonds are responsible for the high surface tension of water and its ability to form drops or beads. In other words, the cohesive forces between water molecules are stronger than the adhesive forces between water and other materials.

However, the strength of adhesion in water can vary depending on the nature of the surface or material it comes into contact with. For example, water is strongly attracted to polar surfaces such as glass, which has a high affinity for water due to its polar nature. This is why water will form a meniscus or rise up a glass capillary tube through capillary action. On the other hand, water is less attracted to non-polar surfaces such as wax or oil, which have a low affinity for water, and will tend to bead up or form droplets on these surfaces.

In summary, while both cohesion and adhesion are important factors in determining the behavior of water, cohesion is stronger than adhesion in water due to the strong hydrogen bonding between water molecules.

Answer 2

Answer: The adhesion of the molecules to the glass is stronger than the cohesion among the molecules.

Step-by-step explanation:

Since water forms a concave up meniscus, the adhesion of the molecules to the glass is stronger than the cohesion among the molecules. However, in the absence of the adhesive force (when water reaches the tip of the glass), the cohesive force remains present. Thus cohesive force alone proves that it can still hold itself in place without pouring out of the cylinder. This example emphasizes the importance of that cohesive force and adhesive forces do not simply cancel each other out, yet it is the difference between the two that determines the characteristic of the liquid.