Aluminium is obtained by
- reducing $Al_2O_3$ with coke
- electrolysing $Al_2O_3$ dissolved in $Na_3AlF_6$
- reducing $Al_2O_3$ with chromium
- heating alumina with cryolite
The Correct Option is B
Approach Solution - 1
Approach Solution -2
The electrolysis of Al2O3 dissolved in Na3AlF6 yields aluminum. Because pure aluminum oxide has a high melting point, it is combined with cryolite to reduce the melting temperature from 200\(^{\circ}\)C to 600\(^{\circ}\)C.
The following equations depict the electrolysis of molten bauxite in the presence of cryolite:
Al+3+3e-→Al (At the cathode)
C +2O2-→CO2 + 4e- (At the anode)
During the electrolysis process, positively charged aluminum ions move towards the cathode, while negatively charged oxygen and fluoride ions move towards the positively charged anode, Because oxygen is less electronegative, it is discharged over fluoride as carbon dioxide gas in reaction with the carbon anode.
Top Questions on General Principles and Processes of Isolation of Elements
A parallel plate capacitor with plate area \(A\) and plate separation \(d = 2\) m has a capacitance of \(4\mu F\). The new capacitance of the system if half of the space between them is filled with a dielectric material of dielectric constant \(K = 3\) (as shown in the figure) will be:
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- An oil drop of radius \(1 \, \mu{m}\) is held stationary under a constant electric field of \(3.65 \times 10^4 \, {N/C}\) due to some excess electrons present on it. If the density of the oil drop is \(1.26 \, {g/cm}^3\), then the number of excess electrons on the oil drop approximately is:
[Take, g = 10 m/s2]- BITSAT - 2024
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A gas can be taken from A to B via two different processes ACB and ADB. When path ACB is used, \( 60 J \) of heat flows into the system and \( 30 J \) of work is done by the system. If path ADB is used, the work done by the system is \( 10 J \). The heat flow into the system in path ADB is:
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- A particle of mass \( 2 \) kg is on a smooth horizontal table and moves in a circular path of radius \( 0.6 \) m. The height of the table from the ground is \( 0.8 \) m. If the angular speed of the particle is \( 12 \) rad/s, the magnitude of its angular momentum about a point on the ground right under the center of the circle is:
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A block of mass 1 kg is pushed up a surface inclined to horizontal at an angle of \( 60^\circ \) by a force of 10 N parallel to the inclined surface. When the block is pushed up by 10 m along the inclined surface, the work done against frictional force is:
[Given: \( g = 10 \) m/s\( ^2 \), \( \mu_s = 0.1 \)]
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Notes on General Principles and Processes of Isolation of Elements
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General Principles and Processes of Isolation of Elements
What are Ores and Minerals?
Minerals are the naturally occurring, homogeneous inorganic solid substances. They are having a definite chemical composition and crystalline structure, hardness and color. For example, copper pyrite, calamine, etc.
Impurities in an ore are called gauge. The removal of a gauge from the ore is called concentration ore.
Several steps are involved in the extraction of pure metal from ores. Major steps are as follows –
- Concentration of the ore
- Isolation of the metal from its concentrated ore
- Purification of the metal