Advertisements
Advertisements
प्रश्न
In the Hall's process for extraction of aluminium, Sate the location of cathode and anode and explain what occurs at each electrode.
उत्तर
Cathode is the inner lining of gas-carbon of the electrolytic cell and anode is the thick carbon rods dipping into the fused electrolytes.
At cathode: Aluminium ions get reduced as:
Al3+ + 3e- → Al
At anode: oxygen gas is liberated as:
O2- - 2e- → [O]
[O] + [O] → O2
The oxygen formed at anode oxidizes the carbon of the anode to carbon dioxide.
C + O2 → CO2
As a result the anode gets oxidized and it has to be replaced periodically.
APPEARS IN
संबंधित प्रश्न
Name the process by which the refining of aluminium is done ?
For graphite, explain its significance in the extraction of aluminium.
Name the following:
The materials used as electrodes in the electrolytic extraction of aluminium.
How is aluminium obtained from pure ore?
For the substance listed below, explain its role in the extraction of aluminium: Sodium hydroxide
In order to obtain one tone of aluminium, the following inputs are required:
4 tones of bauxite, 150 Kg of sodium hydroxide and 600 Kg of graphite.
The aluminium compound in bauxite is aluminium oxide and the main impurity is iron (II) oxide. Aluminium is obtained by the electrolysis of aluminium oxide dissolved in cryolite.
(i) Name the process used for purification of bauxite.
(ii) Write the equation to show the action of heat on aluminium hydroxide.
Write the equation for the reaction that occurs at the cathode during the extraction by aluminium by electrolysis.
Explain with reason:
A neutral gas other than oxygen is formed at the anode during the electrolysis of fused alumina.
Answer the following question:
Write the chemical formula of one main ore of iron and aluminium.
State the relevant reason for the following:
Graphite anodes are continuously replaced during the electrolysis of alumina.
