Question

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

• (a) $\to$ (ii) ,(b) $\to$ (iii) ,(c) $\to$ (i) ,(d) $\to$ (v)
• (a) $\to$ (i) ,(b) $\to$ (ii) ,(c) $\to$ (iii) ,(d) $\to$ (iv)
• (a) $\to$ (iii) ,(b) $\to$ (iv) ,(c) $\to$ (v) ,(d) $\to$ (i)
• (a) $\to$ (iv) ,(b) $\to$ (ii) ,(c) $\to$ (iii) ,(d) $\to$ (i)

Answer 1

The Correct Option is D

Cyanide process: $ {4Au + 8NaCN + O_2 + 2H_2O \to 4Na[Au(CN)_2] + 4NaOH}$ Impure $ {2Na[Au(CN)_2] ->[Zn] $\underset{\text{ ppt}}{ { 2 Au}}$ + Na_2 [Zn (CN)_4]}$ froth floatation process $\to$ all sulphide ore's concentrated by froth floatation method. Electrolytic reduction $\to$ Bauxite reduced by electrolytic reduction in the presence of cryolite by Hall herault process Zone refining $\to$ semi conducter's (Ge, Si)are purified by zone refining