Question

Von helmont experiment on water and photosynthesis lab activity​

Answer 1

Explanation:

Jan Van Helmont wanted to prove plants use materials from the soil to perform photosynthesis. So he performed an experiment where he took a pot of soil and a willow seedling and weighed the pot of soil and the willow tree separately. ... After five years of performing photosynthesis he took the tree out and weighed it.

Answer 2

1. Take a potted plant and destarch it by keeping it in dark room for 2-3 days.

2. Now place it in sunlight but donot water it for 1-2 days.

3. After 3-4 days , you will observe that plant starts wilting.

4. Now take its one of the leaves and boil it in alcohol for 20-25 minutes.Now cool it and put few drops of iodine solution on it.

5.You will find no color change .  

Explanation:

The above experiment shows that:-

• After destarching, it was left with no starch.
• When we did not water it for long time, it became impossible for it to synthesize glucose.
• No change in color shows the absence of starch.
• This happens because in the process of  photosynthesis ( light reaction) the step of photo oxidation of water did not take place and as a result the dark reaction also did not take place.

This shows that water is essential for the process of photosynthesis.