Question

How many coulombs
of electricity are required to produce 40g of Al from Al3+ solution?

Answer 1

$Al^{3+}+3e^-\Leftrightarrow Al$

here it is clear that, 3 mole electrons require to produce 1 mole of Al.

or, you can say that, 3F {F denotes Faraday } electricity required to produce 1 mole of Al or 27g of Al.

so, electricity required to produce 1g of Al = 3F/27

so, electricity required to produce 40g of Al = (40/27) × 3F

= 40/9 F

= 4.44F

we know, 1F = 96500 Coulombs

so, 4.44F = 4.44 × 96500 = 428,460C

hence, 428,460C electricity required to produce 40g of Al from Al3+ solution.