question_answer 78)

    Match items of Column I with the items of Column II .and assign the correct code.                                     

Column 1	Column 11
A. Cyanide process	1. Ultrapure Ge
B. Froth floatation process	2. Dressing of ZnS
C. Electrolytic reduction	3. Extraction of Al
D. Zone refining	4. Extraction of Au
	5. Purification of Ni

            Codes       A  B   C   D                         A   B   C   D (a) 4   2   3   1                       (b) 2   3   1   5 (c) 1   2   3   4                       (d) 3   4   5   1

Answer:

                       ;                 A.®(4)  B.®(2)   C.®(3)   D.®(1) A. Cyanide process is used for extraction of Au through formation of anionic complex. B. -Froth floatation process is used for dressing of ZnS. C. Electrolytic reduction method is used for extraction of aluminium. Graphite electrode is used for this purpose. D. Zone-refining is used for purification of Ge.