Pepper and Soap Experiment:

Items Required:

1. Bowl
2. Water
3. Grounded Pepper
4. Dish soap

Experiment:

1. Fill half the bowl with water.

2. Sprinkle Grounded Pepper evenly across the surface. (Avoid Inhaling !!!)

3. The pepper flakes should float upon the surface of the water.

4. Put a tiny bubble of dish soap onto a clean Surface.

5. Touch the bubble of dish soap with your finger tip. (You just want a tiny amount of soap on the tip of your finger)

6. Now try to touch the pepper in the bowl and see what happens.

Observation:

Most of the pepper flakes should have pushed to the sides of the bowl, and some of the flakes should have fallen to the bottom of the bowl. It may have looked like the soap was chasing the pepper flakes away.

Conclusion:

1. Try to find why pepper flakes float instead of sinking or dissolving in water.

Pepper is not soluble in water because water is very polar and the components of pepper are non-polar.

In other Words:

Water molecules have a strong attraction to other water molecules which gives a good surface tension for water. Pepper flakes are unable to break through the surface tension of the water and hence floats.

2. Can you guess why pepper flakes shoot to the sides when soap touches the water?

Soap is able to break down the surface tension of water. As soon as the soap comes in contact with water, the surface tension of water changes,   so the pepper that comes in contact
with soap no longer floats on top. But the water molecules still want to keep the surface tension going, so they pull back away from the soap and carry the remaining pepper flakes along with them.