Saturday, August 30, 2008
I spent quite some time surfing the net regarding the hydrilla-funnel-test tube setup (which aims to test for the presence of oxygen released during photosynthesis).
Remember? I wasn't sure whether the water in the test tube should cover the mouth of the funnel.
I'm very certain now that the funnel mouth has to be filled with water in the test tube.
The setup MUST look like this, as in the ones shown in your Prelim Science paper.
I gathered the following information:
- The oxygen produced through photosynthesis would appear as bubbles in the water.
- These bubbles would then float up through the funnel and test tube.
- The bubbles would break at the water surface to release the oxygen, thereby displacing the water in the test tube (that's why the water level in the test tube should DECREASE) and causing the gas column in the test tube to INCREASE in length.
Hope there are no more doubts henceforth.
For an animated version of the experiment, click on the following link:
http://www.cellplc.com/class8-10/biology.swf
Yours truly!
Labels: school
9:42 PM