General Principles and Processes of Isolation of Elements
Lead obtained from galena ore (PbS) by air reduction or carbon reduction process contains base metal (Cu, Bi, As, Sn, Zn) as impurities. Gelatin acts as an addition agent in the electrolysis of Pb. In the presence of gelatin, Pb becomes :
- hard and brittle
- soft and rubbery
- smooth and uniform
- only brittle
Correct Answer: Option(c)
Lead obtained contains impurities like which make it hard. During electrolytic refining of lead, the electrolyte is mixed with a little gelatin. Gelatin is added for smooth and uniform deposition of lead in this process.
Hence, the correct option is (C).