NEET Practice Questions (MCQs) with Answers & Solutions

(a)

A mordant is any substance which can be fixed to the fibre and which can be dyed later on. Mostly hydroxides or basic salts of chromium, aluminium and iron are used as mordants. A dye which imparts different colours in the presence of different mordants is referred to as a mordant dye, eg, alizarin is a mordant dye. When mordanted with aluminium salt solution, it imparts rose-red colour to fabric but the same fabric is dyed blue when it is mordanted with barium salt and it dyes violet is mordant with ferric salt.

(c) Disperse dyes are usually applied in the form of dispersion of finely divided dye in a soap solution in the presence of phenol, cresol, benzoic acid, etc. They are mainly used to dye decron, nylon, synthetic fibre. Celliton fast pink B and celliton fast blue B are common examples.

(b)

It is well known that cotton fibres can be dyed through the formation of coordinate bonds involving cellulose chains, mordants such as alum, and natural dyes such asalizarin. Similarly, synthetic dyes known as mordant acid dyes can be used to dye wool fibres.

(a) Follow preparation of malachite green.

(c)

flash paper, flash cotton, guncotton, and flash string) is a highly flammable compound formed by nitrating cellulose through exposure to nitric acid, or to a mixture of nitric acid and another acid, usually either hydrochloric acid or sulfuric acid, 

(b)

(a) The medicines which are used to reduce pain are known as analgesics. For example paracetamol, ibuprofen, morphine, etc.

(b) The chemicals which either prevent the growth of microorganisms or kill them but are not harmful to the living tissues are known as antiseptics. e.g. savlon, dettol. Dettol is one of the most commonly used antiseptics. It is a mixture of chloroxylenol and α-terpineol

(c) The chemical substances which are used to bring down body temperature during fever are called antipyretics, e.g. aspirin, novalgin, etc.

(d) The chemicals which are obtained from microorganisms such as bacteria, fugni etc., or by synthetic methods and used to inhibit the growth or even kill the microorganisms are called antibiotics, e.g. penicillin, chloramphenicol, etc.

(d)   - Novalgin (Dipyrone) is a non-narcotic analgesic used as pain reliever

       - Penicillin is an antibiotic used for curing rheumatic fever

       - Streptomycin is an antibiotic drug

       - Chloromycetin is an antibiotic drug