Question
Chemistry Question on Chemistry in Everyday Life
An insoluble dye is reduced to a soluble colourless leuco form by an alkaline reducing agent. The fibre is soaked in the dye solution and then exposed to air to develop the colour. The dye is
A
mordant dye
B
vat dye
C
azo dye
D
direct dye
Answer
vat dye
Explanation
Solution
Vat dyes are insoluble in water and cannot directly applied. It is reduced to soluble colourless leuco form by an alkaline reducing agent, e.g.,