Soap and Pepper Experiment

Washing hands properly is an effective way to prevent germs from spreading and causing infection. In fact, amid COVID 19 pandemic, hand washing matters more than ever. The science has been clear for years: washing hands with soap can cut down on being sick, but we don’t do it enough and properly at times.

During such an outbreak, teaching kids the importance of washing their hands with soap and sticking to a consistent schedule becomes more crucial. With this easy science experiment of soap and pepper, children can learn how soap fights with germs and science of surface tension of water.

Material Required

• Liquid Soap
• Black Pepper
• Shallow Dish
• Water

Instructions

1. Pour water in the shallow dish.
2. Sprinkle black pepper across the surface of the water.
3. Put your finger in the centre of the dish with pepper on the surface; did anything happened? Some pepper will get stick to your finger and consider them as germs.
4. Now dip the finger in liquid soap.
5. Put that finger dipped in the soap, back in the centre of the dish. You will notice that those pepper flakes will chase to the edges of the dish and away from your finger this time. THE MAGIC OF SOAP TO FIGHT WITH GERMS happened.

The Science Behind It

This experiment is based on the science of surface tension of water. Surface tension is the tendency of liquid surfaces to shrink into the minimum surface area possible which results from the greater attraction of liquid molecules to each other at the surface.

Whereas the grease molecule in soap which attaches to dirt repels the water molecule which is called as hydrophobic. By attempting to move away from the water molecules, the hydrophobic ends of the soap molecules push up to the surface which results in weakened hydrogen bonds holding the water molecules together at the surface. Thereby, breaking the surface tension of the water.