Question

What is the time required to deposit one millimole of aluminium by passage of 9.65 ampere through aqueous solution of aluminium ions?

Options

• 10 sec.

• 300 sec.

• 30 sec.

• 100 sec.

Answer 1

30 sec.

Explanation:

Moles of product formed = `("I" xx "t")/96500 xx "mole ratio"`

\[\ce{Al^{3+} + 3e^- -> Al}\]

∴ Mole ratio = `1/3` = 0.33

∴ 0.001 mol = `(9.65 xx "t")/96500 xx 0.33`

`(0.001 xx 96500)/(9.65 xx 0.33)` = t

∴ t = 30.30 sec.