Question

Cassiterite ( SnO₂) and ore of Tin contains FeWO₄ & MnWO₄ as impurities as well as small amounts of sulfur. SnO₂ is melted with cold, Lime stone and sand in a reverberatory furnace. The impure Tin Sn is purified by liquation

I.  The ore is concentrated by 

(A)  Froth flotation 

(B)  Magnetic separation 

(C)  Leaching 

(D)  a & b

II. The impurities of sulfur can be removed by 

A) Treatment with NaOH 

(B)  Treatment with HCl 

(C)  Roasting 

(D)  Calcinations

III.  If limestone and sand are added during smelting the nature of impurities are

( A)  Acidic and basic 

(B)  Amphotric 

(C)  Acidic 

(D)  Basic

(a)   i-B, ii-C, iii-C

(b)   i-C, ii-D, iii-D

(c)   i-A, ii-C, iii-B

(d)   i-A, ii-C, iii-A

Answer 1

(d)   i-A, ii-C, iii-A, iv-B