MATERIAL REQUIRED
Beaker, short stem funnel, test tube, spirogyra or hydrilla plant, sodium bicarbonate.
THEORY
The process in which green plant prepare their food in their body by using carbon dioxide and water in presence of sunlight absorbed by chlorophyll called photosynthesis.
Water + Carbondioxide ➡ Glucose + Oxygen
6H2O + 6CO2 ➡ C6H12O6 +6O2↑
PROCEDURE
- Put a fresh hydrilla plant in a large beaker and invert the funnel over it.
- Pour water in the beaker till the end funnel sinks completely under the water.
- Fill the test tube with fresh water keeping its mouth closed with your finger; invert it over the funnel.
- Put the apparatus in the bright sunlight for some hours. Observe it.
OBSERVATION
Tiny bubbles escaping from the plant under the funnel and they are collected in the test tube by displacing the water downwards. When a glowing splinter is taken in the gas, it burns brightly.
RESULT
The collected /evolved gas was oxygen.
CONCLUSION
Hence, we can demonstrate that oxygen evolved during photosynthesis.
PRECAUION
- Apparatus should be handle with care.
- There should not be air bubble during fitting test tube.
- Hydrilla or Spirogyra must be healthy and fresh.
- Few pinches of sodium bicarbonate should be added to enhance rate of photosynthesis.
- Experiment should be kept in direct sunlight.