What happens to the surface tension of a liquid when a surfactant is added?

₹0.0

Question: What happens to the surface tension of a liquid when a surfactant is added?

Options:

Correct Answer: Decreases

Solution:

Surfactants lower the surface tension of liquids by disrupting cohesive forces between molecules.

What happens to the surface tension of a liquid when a surfactant is added?

What happens to the surface tension of a liquid when a surfactant is added?

Step 1: Understand what surface tension is. It is the force that makes the surface of a liquid behave like a stretched elastic sheet.
Step 2: Know that liquids are made of molecules that attract each other. This attraction creates cohesive forces.
Step 3: Learn what a surfactant is. A surfactant is a substance that can reduce the surface tension of a liquid.
Step 4: When a surfactant is added to a liquid, it spreads out on the surface and interferes with the cohesive forces between the liquid molecules.
Step 5: As a result of this interference, the surface tension of the liquid decreases.

Surface Tension – The cohesive forces between liquid molecules at the surface that create a 'film' effect.
Surfactants – Substances that reduce the surface tension of a liquid by disrupting intermolecular forces.
Cohesive Forces – The attractive forces between like molecules that contribute to surface tension.