Cohesion & Adhesion

Cohesion: Due to inter-molecule attraction, liquids can with-stand slight tension. the inter-,olecule attration is known as Cohesion.

Adhesion: Cohesion is between molecules of the same fluid whereas adhesion is the property by which molecules of differrent fluids are attracted to one another or molecules of a fluid are attracted to by molecules of a solid. Liquids stick to the wall of vessel by the property of adhesion.

Cohesion (chemistry)

Cohesion (n. lat. cohaerere "stick or stay together") or cohesive attraction or cohesive force is the action or property of like molecules sticking together, being mutually attractive. This is an intrinsic property of a substance that is caused by the shape and structure of its molecules which makes the distribution of orbiting electrons irregular when molecules get close to one another, creating electrical attraction that can maintain a macroscopic structure such as a water drop.

Mercury in a glass flask is a good example of the effects of the ratio between cohesive and adhesive forces. Because of its high cohesion and low adhesion to the glass, mercury does not spread out to cover the bottom of the flask, and if enough is placed in the flask to cover the bottom, it exhibits a strongly convex meniscus, where the meniscus of water is concave . Mercury will not wet the glass, unlike water and many other liquids,^[1] and if the glass is tipped, it will 'roll' around inside.