Question

What characteristic of water causes water to stick to the side of a test tube?

Answer 1

Answer:

The characteristic of water that makes this liquid stick to the side of a test tube is called capillarity (Claim).

Explanation:

Water (H₂O) is a polar molecule with the ability to generate van der Waals forces, which is explained by the 4 hydrogen bonds it forms to bind to other substances. The consequence of the forces of the molecular bonds are four properties of H₂O, including surface tension, cohesion, adhesion and capillarity.

- Claim: The characteristic of water that makes this liquid stick to the side of a test tube is called capillarity.

- Evidence: Cohesion and adhesion of water are properties that come from the forces of the molecular bonds of water, and whose effect is the ability of water to wet surfaces and adhere to a tube that contains it, the latter due to capillarity. Capillarity also allows water to rise through the roots and stems of plants, through their thin vascular ducts.

- Reasoning: cohesion in water depends on the force of attraction between H₂O molecules, adhesion is the capacity of H₂O molecules to join other different molecules and —together with surface tension— make H₂O molecules close to the walls of a glass tube adhere to it, which represents capillarity.

The effect of capillarity is more evident when the test tube is of a smaller diameter, although capillarity and adhesion to its walls always exist, and to a greater degree than any other substance.