Dyes and Pigments MCQs: CSIR | GATE | JAM | SLET
These multiple-choice questions (MCQs) are based on the topic Dyes and Pigments asked in exams like CSIR NET Chemical Sciences, GATE Chemistry, IIT JAM Chemistry, and SLET.
Must read: Comprehensive Notes: Dyes
CSIR NET Chemical Sciences, June 2018
1. Which of the following is an example of an azo dye?
(a) Malachite green
(b) Indigo
(c) Orange-I
(d) Martius yellow
GATE Chemistry, 2020
2. The principal chromophore in azo dyes is:
(a) C=N
(b) N=N
(c) N≡N
(d) C≡N
IIT JAM Chemistry, 2019
3. Auxochromes in dyes are groups that:
(a) Impart color to the dye
(b) Modify the color and increase solubility
(c) Act as the main color-producing unit
(d) Make the dye insoluble
CSIR NET Chemical Sciences, December 2017
4. Which of the following is a vat dye?
(a) Alizarin
(b) Indigo
(c) Congo red
(d) Methyl orange
GATE Chemistry, 2016
5. The difference between dyes and pigments is that pigments are:
(a) Soluble in water
(b) Insoluble and used in suspension
(c) Always organic
(d) Used only for textiles
IIT JAM Chemistry, 2021
6. An example of a natural pigment is:
(a) Phthalocyanine
(b) Titanium dioxide
(c) Carmine
(d) Azo red
SLET Chemistry (Maharashtra), 2015
7. The group -OH is an example of:
(a) Chromophore
(b) Auxochrome
(c) Both
(d) Neither
CSIR NET Chemical Sciences, June 2022
8. Methyl orange is an example of:
(a) Acid dye
(b) Basic dye
(c) Indicator dye
(d) Vat dye
GATE Chemistry, 2023
9. According to Witt's theory, dyes must have:
(a) Chromophore only
(b) Auxochrome only
(c) Both chromophore and auxochrome
(d) Neither
IIT JAM Chemistry, 2017
10. Phthalocyanine is used as:
(a) Red pigment
(b) Blue pigment
(c) Yellow dye
(d) Green dye
SLET Chemistry (Tamil Nadu), 2019
11. The chromophore in nitro dyes is:
(a) -NO2
(b) -N=N-
(c) >C=O
(d) -OH
CSIR NET Chemical Sciences, December 2020
12. Which dye is used for cotton and is a direct dye?
(a) Alizarin
(b) Congo red
(c) Indigo
(d) Malachite green