Summary

In this simple demonstration, students will observe a reaction between an acid and an egg white and learn why is important to wear safety goggles in the lab. The reaction is similar to the damage that can be done to your eye if acid comes in contact with it.

Grade Level

High or Middle School

Objectives

By the end of this demonstration, students should be able to

• Understand why wearing protective eye equipment is important in a chemistry lab.

Chemistry Topics

This demonstration supports students’ understanding of

• Lab Safety

Time

Teacher Preparation: 15 minutes
Lesson: 15 minutes

Materials (per class)

• HCl, 6M, ≈10 mL
• Disposable pipette, 1
• Petri Dish
• Raw egg (or a carton of egg whites)
• Safety goggles
• Chemical resistant apron
• Chemical resistant gloves

Safety

• Always wear safety goggles when handling chemicals in the lab.
• Students should wash their hands thoroughly before leaving the lab.
• Students should wear proper safety gear during chemistry demonstrations. Safety goggles and lab apron are required.
• When working with acids, if any solution gets on your skin, thoroughly flush your skin with water.
• Wash the eggs thoroughly in water before disposing of them.
• Consult the Safety Data Sheet for specific information regarding the use of 6M Hydrochloric acid.

Teacher Notes

• Egg whites and the human eyes contain similar proteins. When they come into contact with a strong acid, the proteins break down. The process cannot be reversed – just like you can’t “uncook” an egg.
• Students will observe that the egg white that interacts with the acid changes from a clear/transparent color to form a distinct white color, similar to what can be observed as an egg is cooked.
• If you have an overhead projector available you can show the reaction to the entire class at one time (it will also be seen much larger).
• If you do not have the equipment or time needed to complete this demonstration in person, you could instead show a short video (~2 minutes) of the demonstration from ScienceFix.
• Flinn Scientific also offers a great teacher resource with tips for getting students to wear their goggles.
• Demonstration Procedure

1. Place a raw egg (out of shell) or egg whites in a petri dish.
2. Used the pipette to put small drops of the acid on the egg white.
3. Have students observe what happens to the egg.
4. Lead a short discussion of the importance of wearing protective eyewear at all time when working in the lab.