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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:
Carbon anodes are used in the electrolytic extraction of aluminium.
Give the chemical name and formula of 'cryolite'
Name a non-metallic element which forms acidic and neutral oxides
Name a non-metallic element which has a metallic lustre
Name a non-metallic element which is a liquid at ordinary temperatures
Name a non-metallic element which is a conductor of electricity.
Write balanced equation for the following reaction:
Reduction of iron (III) oxide by carbon monoxide.
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) Write the formula of cryolite.
(ii) Write down the word which correctly completes the following sentence.
"By dissolving aluminium oxide in cryolite, a ______ (conducting / non- conducting) solution is produced.
(iii) Why so much graphite required for this electrolytic process.
(iv) Write the equation for the reaction which takes place at cathode.
Name the following:
The compound formed by the reaction between calcium oxide and silica.
Write a balanced equation for the reduction of copper (ll) oxide by hydrogen.
