Question

Observe the set-up given in figure and answer the following questions.

1. What happens to the sugar solution in A?
2. Which gas is released in A?
3. What changes will you observe in B when the released gas passes through it? 

Answer 1

1. Yeast grow very rapidly on the sugar containing substrates. It multiplies and increases its number and in process converts the sugar into alcoholic products with the release of CO₂ gas.
   In flask A, fermentation is occurring due to the presence of yeast and its utilisation of sugar.
2. Carbon dioxide is released in A during the fermentation process.
3. The gas released due to the fermentation of sugar in the setup is CO₂. When CO₂ is passed over lime water in set up S its color changes, i.e. the lime water turns milky.