Lesson
Purpose of the work:
- Experimentally confirm the release of carbon dioxide during human respiration
Expected results:
After completing the work, students can:
- develop teamwork skills
- be able to analyze and summarize the information received
- draw logical conclusions
Teacher’s Guide:
- The task is performed in pairs.
- Before starting laboratory work, please read the safety rules by following the link:
- To download the worksheet, follow the link:
Theoretical part
Breathing is a vital process in which the body receives oxygen and releases carbon dioxide. Oxygen is necessary for the oxidation of nutrients and energy production. Carbon dioxide is an oxidation product that is removed from the body. When we exhale, we not only emit carbon dioxide, but also water vapor. Water vapor is formed in the lungs during gas exchange.
Practical part
Experiment 1.
Step 1. Prepare lime water. To do this, dissolve a small amount of calcium oxide in water.
Step 2. Let it settle and filter.
Step 3. Take a clean tube. Dip one end of the tube into a beaker with lime water. Take the other end of the tube into your mouth and slowly exhale through it. Observe the changes.
Experiment 2.
Step 4. Take a clean mirror and breathe onto it. What are you observing? Draw conclusions.
Conclusion
Respiration is a complex physiological process, as a result of which the body receives oxygen and releases carbon dioxide and water vapor. The conducted experiments allowed us to demonstrate these processes clearly.