Question

Malia was able to make a paperclip float on the surface of water. What will most likely happen to the paperclip if a drop of dishwashing detergent is added near it?

Answer 1

Answer: C) Soap is a surfactant that disrupts the intermolecular forces of water making the paperclip sink.

Explanation:

1) This is the set of choices that comes with this question:
A) Soap is a surfactant that increases the intermolecular forces of water allowing the paperclip to continue to float.

B) Soap makes the water less viscous making the paperclip sink.

C) Soap is a surfactant that disrupts the intermolecular forces of water making the paperclip sink.

D) Soap makes the water more viscous allowing the paperclip to continue to float.

2) Justification:

The paperclip is denser that water, so it should sink into the water. Then, why is the paperclip floating?


The papeclip is floating due to the high surface tension of the water.

The surface tension is the force that tends to keep the molecules of a liquid together resisting the spread due to other forces (gravity for example). The surface tension is what makes that a drop of water over a table keeps round and like a hemisphere instead of spreading along all the surface of the table.

That very same force makes it possible that some insects can stand over water and is the responsible for the meniscus that you see in the thin tubes that contain water (e.g. in the test tubes in your chemistry lab).

By the way, that strong intermolecular forces that keep the molecules of water attracted to each other is due the hydrogen bonds.


The soap is a surfactant which reduces the surface tension of the water, this is it disrupts the intermolecular forces of water, and that is what the option C) tells.

Answer 2

Answer:

Soap is a surfactant that disrupts the intermolecular forces of water making the paperclip sink.

Explanation:

Soap is a surfactant, so it will disrupt the surface and make the paperclip fall through.

edg 2020