Question

Silver containing lead as an impurity is not purified by:

• A. Poling
• B. Cupellation
• C. Levigation
• D. Distillation

Answer 1

Answer: (A), (C), (D)

The correct options are
A Distillation
C Poling
D Levigation

Poling is a method employed in the purification of copper which contains cuprous oxide as an impurity. Silver containing lead as an impurity is not purified by polling.

Cupellation is a refining process in metallurgy, where ores or alloyed metals are treated under high temperatures and controlled operations to separate noble metals like gold and silver from base metals like lead, copper, zinc, arsenic or bismuth, present in the ore.

Levigation: The process of removal of heavy ore particles from lighter particles by washing with water. Silver containing lead as an impurity is not purified by levigation.in this process heavy ore particles are removed from a lighter particle. but not lighter particles from heavy particles.

Distillation is a process of separating the component substances from a liquid mixture by selective evaporation and condensation. Distillation may result in essentially complete separation (nearly pure components), or it may be a partial separation that increases the concentration of selected components of the mixture. Ex: zinc and mercury are distilled by a fractional distillation process.

So, silver-containing lead as an impurity is not purified by polling, levigation & distillation.

Hence options A, C, D are correct.