Chemistry of Textile Fibers, Dyes, and Detergents Quiz

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ü The substance appears white when the white light falls on the substance and all colors are reflected.

ü The substance appears black when the white light is completely absorbed.

<p>ü When the substance absorbs only a single band, it will have the complementary color of the absorbed band</p> Signup and view all the answers

<p>ü Chromophores Unsaturated group that is responsible for the appearance of color in compounds (the chromogen) where it is located. For example: Keto (c=o), nitroso (N=O), Ethylenic (c=c), Azo group (N=N), Nitro (NO2).</p> Signup and view all the answers

<p>ü Auxochromes are groups that increase the intensity of the color and shift the absorption to longer wavelength. Auxochrome may be either acidic or basic like -OH or -NH2. Other auxochromes include -COOH, -SO3H, -NR2. These groups form salts with either acids or alkalis. They also form hydrogen bonds with certain groups (-OH of cellulose or NH2 of wool, silk). When the auxochrome are present in the chromogen a dye is obtained</p> Signup and view all the answers

<p>ü The chromogen is a chemical compound that is either colored or could be made colored by the attachment of suitable substituent. The chromophore and the auxochrome(s) are also part of the chromogen.</p> Signup and view all the answers