Question

In an experiment to prove co2 is given out during respiration why is koh hung in the conical flask

Answer 1

This is because KOH absorbs CO2 gas and this helps us to prove the importance of CO2 in photosynthesis as once the CO2 is absorbed, there is no CO2 left in the plants and then we just keep one plant open in the air so that it takes in CO2 and coat the other with Vaseline so that CO2 is not taken in. Then we compare both the plants by iodine test to know which plant has gone through with the process of photosynthesis and this proves the needful..

Hope it's clear