When water is added to a graduated cylinder, having a surface where the sides of the water look higher than the center means that the curved surface is a concave meniscus which has formed because of surface tension (Choice C).
Explanation:
A meniscus is simply the curvature that the surface of a liquid acquires when it is in a container, such as a graduated cylinder. It is concave when there is attraction between molecules -water and glass- or it can be convex when both surfaces are repelled.
<u>Water is a polar molecule</u>, with the capacity to adhere to the surfaces it comes into contact with. This characteristic causes it to form a concave meniscus, as the outermost molecules adhere to the glass surface, while the surface tension of the water attracts the molecules from the centre downwards, causing the concavity.
Which of the following identifies this phenomenon and explains how it is formed?
Choose 1 answer:
(Choice A, Checked, Correct)
CORRECT (SELECTED)
The curved surface is a concave meniscus which has formed because of capillary action.
Capillary action occurs because the water molecules are more attracted to the cylinder than they are to each other. This causes the upward movement of the water along the sides of the glass, forming a curved surface called a concave meniscus.