1P15: Bouncy Raw Egg with Moving Waters
Purpose: To demonstrate osmosis in living eggs
Step 1: Place a quail's egg in a beaker. Fill the beaker with dilute hydrochloric acid.
Bubbles of colourless and odourless gas seen with white froth
Inference:The egg shell is chemically reacting with the dilute hydrochloric acid and a gas was evolved.
Step 2: Soak the egg in the acid for bout 15 minutes, stirring with a glass rod occasionally
Step 3: After about 15 minutes, pour away the acid from the beaker
Step 4: Carefully rinse the egg with tap water and examine it.
Step 5: Describe how the egg feels to the touch.
Step 6: Measure and record the length of the egg.
Experimenting with the egg
1. Fill half a beaker with tap water and put the egg into the beaker.
2. After 30 minutes, remove the egg from the beaker of water. Describe its hardness and record yourobservation.
3. Put the egg back into the beaker of water. Describe the hardness of the egg and record your observation .
Inference from observations
Osmosis has occured. Water has moved from a region of higher water concentration in the beaker to a region of lower concentration in the egg across the partially permeable egg membrane. Thus the egg becomes harder/ turgid.
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