Question

Metals are refined by using different methods . Which of the following metals are refined by electrolytic refining ?
a. $ Au $ b. $ Cu $ c. $ Na $ $ $ d. $ K $
i. a and b
ii. a and c
iii. b and c
iv. c and d

Answer 1

Hint :Hint: In order to answer this question let us first understand refining of metals. Refining is the process of removing impurities from metals in order to produce high-purity metals. Impurities are extracted from crude metal using a variety of methods depending on the metal's and impurities' properties. The following are some of the methods used in the purification of crude metal:
-Liquor for Distillation
-Refining in the Electrolysis Zone
-Refining in the vapour phase
-Methods of chromatography

Complete Step By Step Answer:
Now, as per question demand we will talk about electrolytic refining. Electrolytic refining is the method of electrolysis used to refine a metal (usually copper). When it comes to the mechanism of the operation, a large chunk or slab of impure metal serves as the anode, while a thin strip of pure metal serves as the cathode. Depending on the metal, an electrolyte (metal salt aqueous solution) is often used in this configuration.
When a high-voltage electrical current is used to dissolve impure metal at the anode, clean or pure metal is produced at the cathode. Electrorefining is a term used to describe electrolytic refining.
The following are some of the main minerals' electrolytic refining processes:
Gold: Hydrochloric acid is used as an electrolyte in the electrolytic gold refining process. The cathode is a thin layer of gold, and the anode is a gold alloy. As ion transfer occurs, the cathode receives pure gold with a higher purity rate. The Wohlwill cycle is another name for this procedure.
Sliver: Similarly, the anode is made of crude silver, while the cathode is made of more polished silver. The electrolytic process is the same as the one described previously. The only exception or distinction is that the silver anodes are dissolved in a nitric acid bath. As a result, 99.9% pure silver is obtained.
Copper: Copper is moved from an impure anode to the cathode of an electrolytic cell in this step. Impurities that are insoluble sink to the floor. This method yields copper that is 99.99% pure copper.
Hence , from the all above given data we can understand that, $ Cu,{\text{ }}Zn,{\text{ }}Ag,{\text{ }}Au $ , and other metals are refined electrolytically. The process for refining impure metals is determined by the nature of the metals as well as the nature of the impurities present. Electrolytic refining is used to process metals such as $ Au $ (gold) and $ Cu $ (copper).
So, the correct option is: (i) a and b.

Note :
Copper is most commonly used in modern times as an electrical conductor. Copper has a high electrical conductivity per unit volume. It can be easily drawn through single or multifilament strings that can be twisted easily and frequently without putting too much strain on the process. Copper wire is easily tinned, has excellent soldering properties, and is corrosion resistant at contact points.