Question

One gas bleaches the colour of the flower by reduction while the other by oxidation. Which of the following are they?

• A. ${NH}_3$ and ${SO}_3$
• B. $Ce$ and $Cu$
• C. ${SO}_2$ and ${Cl}_2$
• D. $H_{2}S$ and $Mn{Cl}_2$

Answer 1

Answer: (C)

${SO}_2$ and ${Cl}_2$

One gas bleaches the colour of the flower by reduction while the other by oxidation. They are $S{O}_2$ and $C{l}_2$ respectively.
(1) Bleaching action of sulphur dioxide
$S{O}_2+2H_{2}O\to H_{2}S{O}_4+2\left[H\right]$
(2) Bleaching action of chlorine is by oxidation.
Chlorine reacts with moisture to form nascent oxygen which oxidises the vegetable colouring matter to a colourless product.
$C{l}_2+H_{2}O\to 2HCl+\left[O\right]$