Question

The figure below represents an experiment performed to demonstrate a particular aspect of photosynthesis. The apparatus was kept in sunlight for almost the whole day. The numeral ‘1’ represents a certain condition inside the flask and the numeral ‘2’ represents a chemical responsible for this condition.

(i) What is the object of the experiment ?

(ii) What is the special condition inside the flask?

(iii) What is the chemical substance numbered ‘2’?

(iv) In what way will the three leaves (A, B and C) differ at the end of the experiment, when tested with iodine solution?

Answer 1

(i) The object of this experiment is to show that CO₂ is necessary for photosynthesis.

(ii) The special condition inside the flask is that there is no CO₂ in the air as it has been absorbed by the KOH.

(iii) KOH or NaOH pellets.

(iv) Leaf A will be yellowish-white. Leaf B and Leaf C will turn blue-black.