The model will only work if there are no leaks. Then pull the bottom balloon gently and observe what happens to the small balloons. This experiment will show that carbon dioxide is one of the major cellular metabolic waste products. Place about a teaspoon of lime powder in a cup or glass of warm water and mix thoroughly. Cover the glass and let remain over night.
Next day drain the clear fluid off the top of the solution.
This is the lime water for the experiment. Place the straw in the lime water and blow into the straw. Observe what happens to the clear fluid. This experiment will demonstrate lung capacity by measuring the amount of air that can be forced out of the lungs. Place a strip of masking tape down the side of the milk jug from the top to the bottom.