Advertisements
Advertisements
प्रश्न
what is the function of cryolite in the extraction of aluminium, other than acting as a solvent for bauxite?
Advertisements
उत्तर
Cryolite is used in the electrolysis of alumina. The function of cryolite is to
(i) Reduce melting point of alumina
(ii) Make molten alumina a good conductor of electricity.
APPEARS IN
संबंधित प्रश्न
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 ____________. (Fe/Mg/Pb/Al)
How is the following metallic oxide reduced? Write equations:
Iron (ll) oxide
Write a balanced chemical equation for each of the following reactions :
(i) Reduction of copper (II) oxide by hydrogen
Give equation for the following conversion:Aluminium to sodium aluminate.
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?
Name the following:
The compound formed by the reaction between calcium oxide and silica.
Name the following :
A metal oxide that can be reduced by hydrogen
Write the observation for the following:
A paper dipped in potassium permanganate solution is put on the mouth of a test tube containing sulphur dioxide gas.
- 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
- Write down the three letters each from the above list which are relevant to
- Zinc
- Aluminium
- Fill in the blanks using the most appropriate words from A to F.
- The ore from which aluminium is extracted must first be treated with ………………. so that pure aluminium oxide can be obtained.
- Pure aluminium oxide is dissolved in ….. to make a conducting solution.
iii. Write the formula of cryolite.
Give the equation for the reduction of Iron (III) oxide.
