Question

Is capillary action due to cohesive or adhesive forces, or both?

a) Cohesive forces.
b) Adhesive forces.
c) Both cohesive and adhesive forces.
d) Neither cohesive nor adhesive forces.

Answer 1

Capillary action is the result of both cohesive and adhesive forces. It involves a liquid rising or being suppressed in a narrow tube based on the relative strength of these forces, creating a meniscus that can be either concave or convex.

Step-by-step explanation:

Capillary action is due to both cohesive and adhesive forces. Cohesive forces are the intermolecular forces that hold a liquid together, while adhesive forces are the attractive forces between a liquid and the substance that composes the capillary. When a liquid like water is introduced into a capillary tube, for example, a thin glass tube, adhesive forces cause the water to cling to the glass, causing the water to rise. This rise is due to the adhesive forces being stronger than the cohesive forces within the water. However, if a liquid like mercury, which has stronger cohesive forces than adhesive forces with glass, is introduced, the mercury will depress in the capillary tube, creating a convex meniscus.