Question

In the electrolytic refining of a metal M, what would you take as the anode is :
A. Impure metal M
B. Thin strip of pure metal M
C. Solution of salt of the metal M
D. None of these

Answer 1

‌ Firstly we should be clear what exactly is the refining of metal. Refining of metal is the process to remove impurity from a metal and obtain pure metal which can be used for requirement. Because impurity affects many properties of matter.

Complete answer:
Firstly we should be aware of the concept of anode and terms associated with it .
An anode is an electrode through which the conventional current enters into a polarized electrical device. This contrasts with a cathode, an electrode through which conventional current leaves an electrical device. A common mnemonic is ACID, for "anode current into a device".
A rod of impure metal M would be used as an anode and a thin strip of pure metal M would be used as the cathode. A water-soluble salt of metal M would be used as an electrolyte. When current is passed through the electrolyte, the impure metal from the anode is dissolved in the electrolyte and an equal amount of pure metal from the electrolyte is deposited on the cathode.
Therefore the correct option is option A, Impure metal M.

Note: An electrolyte is a substance that produces an electrically conducting solution when dissolved in a polar solvent, such as water. The dissolved electrolyte separates into cations and anions, which disperse uniformly through the solvent. Electrically, such a solution is neutral. If an electric potential is applied to such a solution, the cations of the solution are drawn to the electrode that has an abundance of electrons.