Question

How long does it take to deposit $100g$ of $Al$ from an electrolytic cell containing $A{l}_2{O}_3$ using a current of $125$ ampere?

• A. $8577.8second$
• B. $857.8second$
• C. $577.8second$
• D. $87.8second$

Answer 1

The correct option is A $8577.8second$

Half Cell Reduction Reaction:-

$A{l}_{\left(aq\right)}^{3+}+3e^{-}\to A{l}_{\left(s\right)}$.

(i) Mole ratio$=\frac{MolesofAlformed}{molesof{e}^{-}}=\frac{1}{3}$

(ii) Moles of $Al$ produced$=\frac{I\times t}{96500Cmo{l}^{-1}}\times \frac{1}{3}$

$\frac{100g}{27gmo{l}^{-1}}=\frac{I\times t}{96500Cmo{l}^{-1}}\times \frac{1}{3}$

$\therefore t=\frac{100g\times 96500Cmo{l}^{-1}\times 3}{27\times 125\left(C\right)}$

$thereforet=8577.8sec$