Question

If $54$g of silver is deposited during an electrolysis reaction, how much aluminium will be deposited by the same amount of electric current?

• A. $2.7$g
• B. $4.5$g
• C. $27$g
• D. $5.4$g

Answer 1

Answer: (B)

$4.5$g

Faraday's First Law of Electrolysis states that only, According to this law, the chemical deposition due to flow of current through an electrolyte is directly proportional to the quantity of electricity (coulombs) passed through it.

The reaction is,

$Ag+e^{-}\to Ag$ and

By Faraday's first law of electrolysis,

1F of electricity deposits 108g of Ag

$⟹$54g of Ag will be deposited by $\frac{1}{108}\times 54=\frac{1}{2}F$

Now for the reaction, $A{l}^{3+}+3e^{-}\to Al$

3F of electricity deposits 27g of Al $⟹\frac{1}{2}F$ will deposit $\frac{27}{3}\times \frac{1}{2}=4.5g$ of Al