How much air in your breath? in Respiration In Organisms – Class 7 Science Experiment

Chapter Name: Respiration In Organisms

Activity Name: How much air in your breath? in Respiration In Organisms

Activity Description:

Required Items:

1. Two-liter plastic bottle
2. 100 ml injection bottle
3. Measuring cylinder
4. Rubber tube
5. Water
6. Bucket or large container of water

Step by Step Procedure:

1. Create a measuring cylinder by marking water levels in the two-liter plastic bottle. Pour 100 ml of water at a time into the bottle, and mark the water level after each addition.
2. Fill the plastic bottle to the brim and invert it in a bucket or a large container of water, ensuring no air bubbles remain inside the bottle after inversion.
3. Insert one end of the rubber tube into the mouth of the bottle under the water and hold the other end in your hand.
4. Inhale deeply and then blow the air out into the measuring cylinder through the rubber tube. Do not inhale while blowing the air out.
5. Blow out as much air as you can in a single breath, and the air will collect in the measuring cylinder.
6. Measure the reduction in water level in the cylinder, which is equal to the volume of air you exhaled in that breath.

Experiment Observations:

• Note the reduction in water level in the measuring cylinder after exhaling the air.

Precautions:

1. Ensure no air bubbles are trapped inside the plastic bottle before starting the experiment.
2. Use a rubber tube that fits tightly in the bottle’s mouth to prevent air leakage.
3. Perform the experiment in a controlled environment to avoid disturbances.

Lesson Learnt from Experiment:

This experiment demonstrates the volume of air exhaled in a single breath, which is a crucial aspect of the respiratory process in organisms. It helps understand the amount of air exchanged during respiration and highlights individual variations in breathing capacity.