Go To Your Study Dashboard

Get Answers to all your Questions

header-bg

Aluminium oxide may be electrolysed at 1000°C to furnish aluminium metal ( At. Mass = 27 amu 1 Faraday= 96,500 Coulombs ) The cathode reaction is

$Al^{3+}+3e^{-}\rightarrow Al^{0}$ To prepare 5.12 kg of aluminium metal by this method would require

Option 1)
$5.49\times 10^{7}C\: of\: electricity$

Option 2)
$1.83\times 10^{7}C\: of\: electricity$

Option 3)
$5.49\times 10^{4}C\: of\: electricity$

Option 4)
$5.49\times 10^{10}C\: of\: electricity$

Answers (1)

best_answer

As we learnt in

Faraday's first law of electrolysis -

The mass of any substance deposited or dissolved at any electrode during electrolysis is directly propotional to the quantity of electricity passed through the solution.

- wherein

$W\alpha\ Q$

$W=ZIt$

Z = mass of electrolyte get deposited

Z = electro chemical equivalent

From Faraday's 1st law,

$W= Z\times Q\left [ W= weight, Z = electrochemical , Q = quantity \: of \: electricity \right ]$

$E= Z\times F\: \: \left [ E = equivalent \: weight , F = faraday \right ]$

or $W= \frac{E}{F}\times Q$

or $Q= \frac{W\times F}{E}$

$Q= \frac{W\times F}{\frac{A}{n}}$

$\left [ A= Atomic \: weight ,n=valency \: of \: ion \: \right ]$

$or \: Q= \frac{n\times w\times f}{A}$

$or \: Q= \frac{3\times 5.12\times10^{3}\times 96500}{27}= 5.49\times 10^{7}C$

Option 1)

$5.49\times 10^{7}C\: of\: electricity$

This option is correct.

Option 2)

$1.83\times 10^{7}C\: of\: electricity$

This option is incorrect.

Option 3)

$5.49\times 10^{4}C\: of\: electricity$

This option is incorrect.

Option 4)

$5.49\times 10^{10}C\: of\: electricity$

This option is incorrect.

Posted by

Plabita

View full answer

Crack JEE Main with "AI Coach"

HD Video Lectures
Unlimited Mock Tests
Faculty Support

jee_ads

Similar Questions

Trending Articles/News

anam-khan

JEE Main 2023 Session 2 City Intimation Slip Live Updates: NTA JEE Mains admit card at jeemain.nta.nic.in soon

anam-khan

JEE Main 2023 April Session: How e-libraries can help accelerate exam preparation

anam-khan

Fake videos on JEE Main 2023 session 2 admit card, city slip release date circulating, NTA warns

Latest Question