Question

The number of Faradays needed to reduce $4$ g equivalents of $C{u}^{2+}$ to $Cu$ metal will be:

• A. $1$
• B. $2$
• C. $1/2$
• D. $4$

Answer 1

The correct option is D $4$

$\text{According to mole concept:}$

$\text{1 mole of an atom contains number of particles.}$

$\text{We know that:}$

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

$\text{Charge on 1 mole of electrons =}1.6\times {10}^{-19}\times 6.022\times {10}^{23}=96500C$ $(96500C=1Faraday)$

$Q=i\times t$

where Q= quantity of electricity in coulombs

I = current in amperes

t= time in seconds

$C{u}^{2+}+2e^{-}\to Cu$

$\text{2 g equivalent of Cu(II) requires 2 Faraday of electricity}$

$\text{4 g equivalent of Cu(II) requires =4 Faraday of electricity}$