Question

how many grams of Al can be produced in an electrolytic cell containing a solution of aluminum chloride if a current of 10.0 A is applied for 5 hours?

Answer 1

how many grams of Al can be produced in an electrolytic cell containing a solution of aluminum chloride if a current of 10.0 A is applied for 5 hours?

Given: Current = 10.0 A (C/s)

Time = 5 hrs

Solution:

Reaction :

Al3+ +3e- -> Al

From above reaction , 3 mol electrons are required to produce 1 mol Al.

We use this stoichiometric equivalence.

Lets calculate quantity of current :

Q = I t

Q is quantity of current in Coulomb , I = current C/s , t is time in s

Lets convert time in second

Time in s = 5 hrs *( 60 min / 1hr ) * (60 s / 1min )

=18000 s

Q = 10 c/s * 18000 s = 180000 C

We know Faradays constant = 96500 C/mol electron

Lets calculate moles of electrons

#moles of electrons = 180000 C * 1mol electrons / 96500 C

= 1.865 mol electrons

#moles Al from 1.865 mol Electrons

= 1.865 mol electrons * 1 mol Al/ 3 mol electrons       

= 0.622 mol Al

We convert mol of Al to mass of Al

Mass of Al = mol Al * molar mass of Al

= 0.622 mol Al * 26.982 g per mol

= 16.8 g Al

So 16.8 g Al will be produced