Question

What happens when a detergent is added to water?

• A. Surface tension increases.
• B. Surface tension decreases.
• C. Viscosity increases.
• D. Viscosity decreases.

Answer 1

Answer: (B), (C)

Viscosity increases.
Surface tension decreases.

When detergent is added to water, the detergent molecules break down the cohesive attractive forces of the water molecules at the surface. Thus, the surface tension is broken and viscosity increases due to attractive forces between water molecules and detergents.