Solve
Guides
0
You visited us 0 times! Enjoying our articles? Unlock Full Access!
Standard XII
Chemistry
Extraction of Crude Metal from Concentrated Ore
Question

In order to obtain 1 tonne of aluminium, 4 tonnes of bauxite, 150 kg of sodium hydroxide and 600 kg of graphite is required. The aluminium compound in bauxite is aluminium oxide and the main impurity is iron (III) oxide, Aluminium is obtained by the electrolysis of aluminium oxide dissolved in cryolite.
When bauxite is treated with sodium hydroxide solution, what happens to
(i) the aluminium oxide
(ii) the iron (III) oxide

Open in App
Solution
Verified by Toppr

(i) The aluminium oxide forms sodium aluminate.

$$Al_{2}O_{3}.2H_{2}O + 2NaOH \overset{150^{\circ}C - 200^{\circ}C}{\rightarrow} 2NaAlO_{2} + 3H_{2}O$$

(ii) The iron (III) oxides does not dissolve in $$NaOH$$ and is removed by filtration.

Was this answer helpful?
2
Similar Questions
Q1
In order to obtain 1 tonne of aluminium, 4 tonnes of bauxite, 150 kg of sodium hydroxide and 600 kg of graphite is required. The aluminium compound in bauxite is aluminium oxide and the main impurity is iron (III) oxide, Aluminium is obtained by the electrolysis of aluminium oxide dissolved in cryolite.
When bauxite is treated with sodium hydroxide solution, what happens to
(i) the aluminium oxide
(ii) the iron (III) oxide
View Solution
Q2
In order to obtain 1 tonne of aluminium, 4 tonnes of bauxite, 150 kg of sodium hydroxide and 600 kg of graphite is required. The aluminium compound in bauxite is aluminium oxide and the main impurity is iron (III) oxide, Aluminium is obtained by the electrolysis of aluminium oxide dissolved in cryolite.
(i) Name the process used for the purification of bauxite.
(ii) Write the equation for the action of heat on aluminium hydroxide.
View Solution
Q3
In order to obtain 1 tonne of aluminium, 4 tonnes of bauxite, 150 kg of sodium hydroxide and 600 kg of graphite is required. The aluminium compound in bauxite is aluminium oxide and the main impurity is iron (III) oxide, Aluminium is obtained by the electrolysis of aluminium oxide dissolved in cryolite.
In construction work, why is the alloy of aluminium(duralumin) used rather than pure aluminium?
View Solution
Q4

In order to obtain 1 tonner of aluminium, the following inputs are required. 4 tonnes 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 (III) 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?

(b) (i) Name the process used for the purification of bauxite.

(ii) Write the equation for the action of heat on aluminium hydroxide.

(c) (i) Write the formulae 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 is so much graphite required for the electrolytic process?

(iv) Write the equation for the reaction which takes palace at cathode.

View Solution
Q5
In order to obtain one tonne of aluminium, the following inputs are required:
4 tonnes 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 (III) 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?
(b) (i) Name the process used for the purification of bauxite.
(ii) Write the equation to show the action of heat on aluminium hydroxide.
(c) (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 is so much graphite required for this electrolytic process?
(iv) Write the equation for the reaction which takes place at the cathode.
(d) In construction work, why is the alloy of aluminium, duralumin used rather than pure aluminium.
View Solution