Question

Select correct statement regarding silver extraction / purification process.

• A. When the lead-silver alloy is rich in silver, lead is removed by the cupellation process.
• B. Lead is removed from argentiferous lead by Parke’s process.
• C. Zinc forms an alloy with lead, from which lead is separated by distillation.
• D. Zinc forms an alloy with silver, from which zinc is separated by distillation.

Answer 1

Answer: (D)

Zinc forms an alloy with silver, from which zinc is separated by distillation.

Answer 2

(1) Cupellation is used when lead is present in traces.

(2) In argentiferous lead the silver is removed by Parke’s process because silver has higher solubility in molten zinc than lead.

(3) Silver has higher solubility in molten zinc than lead and thus forms zinc-silver alloy from which zinc can be distilled off leaving behind the silver.

(4) Silver has higher solubility in molten zinc and thus forms zinc-silver alloy from which zinc can be distilled off leaving behind the silver.