Carbon dioxide is the gas which is inhaled by plants . Symbol of Carbon dioxide is CO2 . This gas is also evolved by burning.

What is carbon dioxide?

Carbon dioxide (CO2) is a colorless, odorless gas composed of one carbon atom bonded to two oxygen atoms. It is a greenhouse gas that occurs naturally in the Earth's atmosphere, but it is also produced through human activities such as burning fossil fuels, deforestation, and industrial processes.

Experiment to study: What do we Breathe out/Role of Carbon Dioxide during Respiration

In this experiment, we aim to investigate the role of carbon dioxide during respiration by studying what we breathe out.

Materials needed:
1. Clear glass or plastic bottle with a narrow opening
2. Balloon
3. Straw
4. Lime water (calcium hydroxide solution)

Procedure:
1. Pour a small amount of lime water into the bottle.
2. Attach the balloon to the opening of the bottle using the straw.
3. Take a deep breath and blow into the balloon through the straw.
4. After a few breaths, remove the balloon from the bottle and observe.

Observation:
The lime water in the bottle turns milky or cloudy when we blow into the balloon.

Explanation:
When we breathe in, we inhale oxygen, which is necessary for respiration. During respiration, oxygen is used by our cells to break down glucose and produce energy. The waste product of this process is carbon dioxide.

When we exhale, we release carbon dioxide along with some water vapor. This carbon dioxide reacts with the lime water in the bottle, forming a white precipitate of calcium carbonate, which makes the lime water turn milky or cloudy.

Role of carbon dioxide during respiration:
1. Waste product: Carbon dioxide is a waste product produced during cellular respiration. It is removed from the body through exhalation.
2. Transport: Carbon dioxide is carried in the bloodstream to the lungs, where it is released into the air during exhalation.
3. Acid-Base balance: Carbon dioxide helps maintain the pH balance in our blood. It acts as a buffer, regulating the acidity of the blood.
4. Breathing control: High levels of carbon dioxide in the blood stimulate the breathing center in the brain, causing an increase in respiration rate to remove excess carbon dioxide.

Conclusion:
Carbon dioxide is a waste product of cellular respiration that is exhaled from our bodies. It plays important roles in maintaining acid-base balance, transportation in the blood, and regulating breathing. The experiment using lime water demonstrated the presence of carbon dioxide in our breath, as indicated by the milky appearance of the lime water.