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?

A) 27.0
B) 9.00
C) 1.19 × 103
D) 2.90 × 105
E) 3.57 × 103

Answer 1

E)
`3.57* 10^3s`

Step-by-step explanation:

According to mole concept:

1 mole of an atom contains
`6.022* 10^(23)` number of particles.

We know that:

Charge on 1 electron =
`1.6* 10^(-19)C`

So, charge required to deposit 4.00 g of aluminum metal according to the reaction below

`Al^(3+)+3e^-\rightarrow Al`

is:-

Charge =
`(4.00)/(26.98)* 3* 1.6* 10^(-19)* 6.022* 10^(23)=4.29* 10^4C`

To calculate the time required, we use the equation:

`I=(q)/(t)`

where,

I = current passed = 12.0 A

q = total charge =
`4.29* 10^4C`

t = time required = ?

Putting values in above equation, we get:

`12.0A=(4.29* 10^4C)/(t)\\\\t=(4.29* 10^4C)/(12.0A)=3.57* 10^3s`