Rekha and Lekha took two fresh red roses and kept them in two containers A and B into which anhydride of sulphurous acid and a greenish yellow coloured gas are passed respectively. After a few minutes these two roses lose their colour but on being exposed to the atmosphere, it was observed that Rekha' s rose regained its colour but Lekha' s rose did not. How do you account for the above changes?

Rekha and Lekha took two fresh red roses and kept them in two containe

1.	Rekha and Lekha took two fresh red roses and kept them in two containers A and B into which anhydride of sulphurous acid and a greenish yellow coloured gas are passed respectively. After a few minutes these two roses lose their colour but on being exposed to the atmosphere, it was observed that Rekha' s rose regained its colour but Lekha' s rose did not. How do you account for the above changes?
Answer» SOLUTION :ANHYDRIDE of sulphrous ACID is `SO_2` When the TWO fresh red roses are exposed to , `SO_2` and `Cl_2` the roses fade away as both `CO_2`and `Cl_2` act as bleaching agents. Once thesetwo roses are exposed again to air, one of the roses Which is bleached by `SO_2` in jar A regainsits colour.This is due to the reason that `SO_2` bleaches by reduction and once the rose is exposed to air oxidation takes place. However, `Cl_2` bleaches by oxidation