Question

Lead obtained from galena ore (PbS) by air reduction or carbon reduction process contains base metal (Cu, Bi, As, Sn, Zn) as impurities. Which of the following electrolyte is used for electrolysis of Pb ?

• A. $PbS{O}_4+H_{2}S{O}_4$
• B. $PbC{l}_2+HCl$
• C. $PbSi{F}_6+H_{2}Si{F}_6$
• D. none of these

Answer 1

The correct option is C $PbSi{F}_6+H_{2}Si{F}_6$

Electrolytic refining operation of Pb permits the obtaining of the pure Pb from a single operation.

Generally, at the lead factories, the electrolyte is an aqueous solution of fluorosilicate of lead $\left(PbSi{F}_6\right)$ and

fluorosilicic acid $\left(H2Si{F}_6\right)$.

The electrolyte based an H2SiF6 is toxic and very corrosive.