How to make oxygen with the help of a plant
Here is an interesting and entertaining experiment that lies on the borderline of two sciences – chemistry and biology. You can easily repeat it at home and amaze your friends and family.
Reagents and equipment
- solution of baking soda (5 g/l);
- water plant (in our case it is waterweed);
- test tube;
- match or splinter;
Place the water plant in the beaker, cover it with a funnel and fill the beaker with the salt solution, then place a test tube containing water in the funnel. Turn on a bright light and wait for around two to three hours. After the test tube fills completely, carefully remove it from the funnel and hold a smoldering splinter or match up to it. Watch the splinter burn.
Photosynthesis is a complex biochemical process in which light energy transforms into the energy of chemical bonds, or more simply it is a process in which carbon dioxide and water transform into organic substances and oxygen under the impact of light:
СО₂ + Н₂О → Organic substances + О₂
It is easy to prove the presence of oxygen – just lower a smoldering splinter or match into the test tube, and it will immediately flare up, as oxygen is a gas that supports combustion.
Why the solution of baking soda is required: as the carbon dioxide in the air dissolves poorly in water, to increase its concentration we can use carbonates or bicarbonates, which by their nature are salts of carbonic acid (CO₂・H₂O).