Answer to Question #295334 in General Chemistry for golden

Question

State whether each of the following situations is an example of surface tension, capillary action, or adhesion. Include an explanation to support each answer.

1. After it rains, you have water droplets on your car.

2. You see an insect walking on a pond. 

3. You left the end of a towel in a bucket of water. The end that is hanging over the rim of the bucket is wet as well.

Answer 1

a)

Water form droplets on surface of car body because the adhesive force between water and the surface is less than the cohesive forces within water particles.

b)

Insect are able to walk on surface of water due to surface tension. This property results from the cohesive forces between molecules at the surface of a liquid and it causes the surface of a liquid to behave like a stretched rubber membrane.

c)

Towel is porous and water rises through it due to capillary action.

The adhesive forces between the liquid and the porous material combined with the cohesive forces within the liquid, may be strong enough to move the liquid through the towel.