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

Answer:

E) $3.57\times 10^3s$

Explanation:

According to mole concept:

1 mole of an atom contains $6.022\times 10^{23}$ number of particles.

We know that:

Charge on 1 electron = $1.6\times 10^{-19}C$

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

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

is:-

Charge = $\frac{4.00}{26.98}\times 3\times 1.6\times 10^{-19}\times 6.022\times 10^{23}=4.29\times 10^4C$

To calculate the time required, we use the equation:

$I=\frac{q}{t}$

where,

I = current passed = 12.0 A

q = total charge = $4.29\times 10^4C$

t = time required = ?

Putting values in above equation, we get:

$12.0A=\frac{4.29\times 10^4C}{t}\\\\t=\frac{4.29\times 10^4C}{12.0A}=3.57\times 10^3s$