Question

Calculate the mass of aluminium produced when a 6.80 A current is applied to AlCl3 (l) for 1.50 hours.,?

Answer 1

3.4 g

Explanation:

Aluminium is discharged:

`sf(Al^(3+)+3erarrAl)`

This means that 1 mole of Al requires 3 moles of electrons to be discharged.

`sf(Q=It)`

So the charge passed `sf(=6.80xx1.5xx60 xx60=36,720color(white)(x)C)`

The charge on a mole of electrons is referred to the Faraday and = `sf(9.65xx10^(4)color(white)(x)"C/"mol)`

`:.` `sf(3Frarr27gcolor(white)(g)Al)`

`sf(3xx9.65xx10^(4)Crarr27g)`

`sf(28.95xx10^(4)Crarr27g)`

`:.` `sf(1Crarr(27)/(28.94xx10^(4))color(white)(x)g)`

`sf(36,720Crarr(27xx36,720)/(28.94xx10^(4))color(white)(x)g)`

`sf(=3.4color(white)(x)g)`

This is not a good question as solid aluminium chloride sublimes on heating so the electrolyte cannot be molten as described. A better choice would be a solution of aluminium nitrate or similar.