Tip:
Highlight text to annotate it
X
Sulphur dioxide access is a bleaching agent and bleaches vegetable coloring matter in
presence of moisture. You can observe here how moist flower looses color. The bleaching
action sulphur dioxide is due to reducing action.
The color of pigment reduced to a colorless compound.
On standing in an air the color less reduce product is deoxidize and gain the opportune
color. Bleaching with sulphur dioxide is therefor
of temporary nature. It is generally used for bleaching delegate
article like ivory, silk, wool etc.