Question

Explain the electrolytic refining of copper with neat labeled diagram.

Answer 1

Electrolytic Refining of Copper.

⇒ First, take a tank, and fill it with an electrolyte i.e, a solution of Acidified copper sulphate.

⇒ Take a thick strip of impure copper as the anode, and a pure strip of copper as the cathode. Now, connect the electrodes to a electric circuit such that electricity can be passed through it and make sure that the electrodes are immersed in water.

⇒ On passing current through the electrolyte, it can be observed that pure metal from the anode dissolves into the electrolyte, and an equivalent amount of pure copper metal from the electrolyte is deposited on the cathode.

⇒ The impurities that are soluble dissolve into the electrolyte whereas the insoluble impurities settle down at the bottom of the anode and are called anode mud.

 

⇒ Hence, the pure metal is obtained on the cathode.

Chemical Equation at the Electrodes:

$\sf Cathode: \ Cu^{2+}\ + \ 2e^- \longrightarrow Cu$

$\sf Anode: \ Cu  -  2e \longrightarrow Cu^{2+}$

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Important Concepts related to Electrolytic Refining of Metals.

⇒ There are two electrodes used for the electrolytic refining. The Anode that is made the impure metal [Positively charged rod] and the cathode is made as a thin rod of pure copper [Negatively charged rod].

⇒ The electrolyte is a solution of metal salt that is being refined.

⇒ On passing electricity through the solution, the pure metal from the anode dissolves into the electrolyte and a equivalent amount of dissolved pure metal is deposited on the cathode.

⇒ Anode mud is the insoluble impurities that settle down below the anode.

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