Question

How many seconds are required to produce 4.00 g of aluminum metal from the electrolysis of molten AlCl3 with an electrical current of 12.0 A? How many seconds are required to produce 4.00 g of aluminum metal from the electrolysis of molten AlCl3 with an electrical current of 12.0 A? 3.57 × 103 1.19 × 103 9.00 2.90 × 105 27.0

Answer 1

A=
`3.5 x10^3 s`

Explanation:

• Write the electrolysis reaction for Al

`Al^+^3 +3e^- -----> Al`

• Find moles of Al using the molecular weight of Aluminum (26.981 g/mol)

`4 g Al ((1 mol Al)/(26.981 g Al)) =0.148 mol Al`

• Calculate moles of charge using the relation of the electrolysis reaction.

`1 mol Al -----> 3 mol (e^-)`

`0.148 mol Al((3 mol e^-)/(1 mol Al) )=0.444 mol (e^-)`

• Using Faraday's Constant to calculate the quantity of electricity (Coulombs)

`0.444 mol (e^-)((96500 C)/(1 mol (e^-)) )=42846 C`

• Finally, you can obtain the seconds using electrical current of 12 A (12 C/s)

`42846 C ((1 s)/(12 C) )=3570.5 s=3.57x10^3 s`