1. Take a healthy branch of Hydrilla and place it in a funnel. Invert the funnel in a beaker of water as shown in the figure.
2. Invert a test tube over the stem of the funnel.
3. The stem of the funnel should be kept immersed inside the water Leave the beaker in sunlight for some time.
4. You will notice some bubbles rising in the test tube.
5. The bubbles contain oxygen released by the plant during photosynthesis.
6. If we show a glowing splinter to the collected air, it bums brightly.
7. This shows that the collected gas is oxygen
