Dyes: Preparation and properties — DU B.Sc. (Prog.) Applied Physical Sciences with Industrial Chemistry Previous Year Question Papers

Unique.Paper Code DYES : PREPARATION AND PROPERTIES 1. (a) What are the pre-requisites of a dye? (b) Differentiate between bathochromic and hypsochromic shift. (c) Explain the colour and constitution with reference to chromophore-auxo chrome theory. (d) (e) Describe the historical development of dyes from natural to synthetic dye. Mention two harmful effects of dye effluent on human health. (3,3,3,3,3) 2. (a) How can we classify the dyes based on their chemical constitution? Explain by giving examples. (b) (c) What are the limitations of natural dyes? What are factors that affects the fastness properties of dyes? (7,4,4) 3. Give the preparation of any three of the following.dyes with mechanism :` (i) Mala.chite green (iii) Methyl orange (iv) Crystal violet 4. (a) Discuss the batch and continuous process of dyeing. (b) Discuss the dyeing of wool using triphenylmethane dyes. (c) Indicate the fibres for which the following dyes have affinities. (i) Mordant dye (ii) Acid dyes 5. (a) ; (b) Discuss the effect of dye effluent on Environment. Explain the treatment of dye effluent by chemical method, c) What is the waterless dyeing and why it is required. 6. Write short notes on any three of the following : (ii) Disperse dyes (iv) Case-study of Kalamkari