Question

Why does we use of koh helps to show co2 is released during respiration in the germinating seed respiration experiment?

Answer 1

As the solution of freshly prepared koh will react with CO2 and give K2CO3 (potassium carbonate) +h20 and thus the wayer level the beaker filled with water rises indicating the presence of CO2

Answer 2

In the experimental setup to show that germinating seed respire we use KOH or Potassium Hydroxide.

We use KOH because KOH or potassium Hydroxide acts as a carbondioxide absorber.

The container in which germinating seed as kept is sealed with vaseline so that air from outside doesn't reach inside the flask.

When the germinating seeds respire, they produce carbondioxide.

Now,

This carbondioxide is absorbed by potassium hydroxide...

Due to this absorption, Vacuum is Created inside the flask.

So,

Water level rises in the opposite side of the U-Tube dipped in water.

This rise shows that there is vacuum created inside the flask and vacuum is only created when KOH absorbs the gas produced.

This implies that the gas produced is carbondioxide and carbondioxide is produced during respiration.

The reaction which takes place is as follows :-

$\boxed{ \boxed{2KOH + CO_2 \implies K_2CO_3 + H_2O}}$

This is why we use KOH in the experimental set up to check the production of carbon dioxide during respiration.