Difference between inhaled and exhaled air in Respiration In Organisms – Class 7 Science Experiment

Chapter Name: Respiration In Organisms

Activity Name: Difference between inhaled and exhaled air in Respiration In Organisms

Activity Description:

This activity aims to demonstrate the difference between inhaled and exhaled air by observing the temperature of the air. The experiment involves exhaling air from your nose onto the back of your index finger and comparing it to the air pumped from a syringe onto the same finger.

Required Items:

1. Index finger
2. Syringe
3. Awareness and sensitivity to temperature changes

Step by Step Procedure:

1. Place your index finger against your nose and exhale gently onto the back of your finger.
2. Pay attention to the sensation of the exhaled air on your finger.
3. Now, take the syringe and pump some air onto the back of your finger.
4. Observe the sensation and compare it with the exhaled air.

Experiment Observations:

• Exhaled Air: The air exhaled from your nose onto the finger may feel warm.
• Syringe Air: The air pumped from the syringe may or may not feel warm, depending on whether the syringe air is at body temperature or if it was filled with room-temperature air.

Precautions:

1. Be cautious while using the syringe to avoid injury.
2. Ensure the syringe is clean and dry before use.
3. Avoid pumping a large amount of air with force, as it may cause discomfort.

Lesson Learnt from Experiment:

The experiment illustrates that exhaled air from the human body may often feel warmer than the ambient air. The warmth is a result of the respiratory process, where oxygen is taken in, and carbon dioxide is released during cellular respiration. This simple activity helps in understanding the temperature difference between inhaled and exhaled air and its significance in the process of respiration.