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प्रश्न
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.
(a) When bauxite is treated with sodium hydroxide solution, what happens to:
(i) the aluminium oxide?
(ii) The iron (III) oxide?
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उत्तर
(i) Aluminium oxide being an amphoteric oxide reacts with sodium hydroxide solution to form soluble sodium meta aluminate.
\[\ce{\underset{\text{Alumina}}{Al2O3.2H2O} + 2NaOH + 2H2O ->\underset{\text{Sodium aluminate}}{2NaAIO2} + 3H2O}\]
(ii) Iron (III) oxide remains undissolved in the sodium hydroxide solution and settles down.
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संबंधित प्रश्न
Give reason for the following:
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Give equation for the following conversion: Aluminium hydroxide to aluminium oxide.
Name oxide of one metal which is reduced by (give equation): Reduction with carbon
Name a non-metallic element which forms acidic and neutral oxides
If fused metallic chloride is electrolyzed, at which electrode would the metal be obtained?
Answer the following question with respect by hydrogen : Identify the components of the electrolyte other than pure alumina and the role played by each.
Answer the following question with respect by hydrogen :
Explain why powdered coke is sprinkled over than electrolytic mixture.
Complete the following by selecting the correct option from the choices given :
The metal whose oxide, which is amphoteric, is reduced to metal by carbon reduction ________
Give the equations for the reduction of Lead (II) oxide.
The following sketch represents the electroplating of an Iron cup with Nickel metal.
Study the diagram and answer the following questions:
- During electroplating, the iron cup is placed at the cathode. Why?
- Name the ion that must be present in the electrolyte.
- State one condition that is necessary to ensure that the deposit is smooth, firm and even.
- Write the reaction taking place at the cathode.
- What change would you observe at the anode?
