Question

How many coulombs are required to produce 50g of aluminium from aluminium oxide dissolved in cryolite? plz mention what is cryolite?

Answer 1

student-name Srishti Prabhakar asked in Chemistry
How many coulombs are required to produce 50g of aluminium from aluminium oxide dissolved in cryolite?
plz mention what is cryolite?
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student-name Kanika answered this
988 helpful votes in Chemistry, Class V
Aluminium is deposited in the electrolysis process of Aluminium oxide by the following reduction reaction of aluminium ion:

Al+ + 3e- → Al

We can see that. 3 electrons deposit 1 mole of Al = 27g of Al

1 mole of electrons will deposit 1/3 mole of Al = 9g of Al.

50g of Al will be deposited by (50g x 1 mole) / 9g = 5.55 mole of electron.

1 mole of electron contain 96500 C

Therefore, 5.55 mole = (96500 x 5.55) = 535575 C.

Thus, 535575 C of electricity will be needed to deposit 50g of Aluminium.

Cryolite is Na3AlF6. It improves the conductivity of the cell and lowers the melting point of the mixture(Pure Alumina and Cryolite) in the cell.