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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.
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संबंधित प्रश्न
Name the solution used to react with Bauxite as a first step in obtaining pure aluminum oxide, in the Baeyer’s process
Give the chemical names and formulae of the main ores of zinc.
Name the constituents of Bronze.
Give reason for the following:
Aluminium oxide cannot be reduced by carbon.
In the Hall's process for extraction of aluminium, Give the formula and purpose of fluorspar and cryolite
What is the role of cryolite (NaAlF6) in the electrolytic reduction of alumina in the Hall's process?
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.
A to F below relate to the source and extraction of either zinc or aluminium.
- Bauxite
- Coke
- Cryolite
- Froth floatation
- Sodium hydroxide solution
- Zinc blende
Fill in the blanks using the most appropriate words from A to F:
(i) The ore from which aluminium is extracted must be treated with ______ so that pure aluminium oxide can be obtained.
(ii) Pure aluminium oxide is dissolved in ______ to make a conducting solution.
In Hoope's process, pure aluminium is collected at the ______ of the electrolytic cell.
Answer the following question:
Write the chemical formula of one main ore of iron and aluminium.
