Question

The standard reduction potential of $E_{B{i}^3+/Bi}^{\circ }$ and $E_{C{u}^{2+}/Cu}$ are $0.226V$ and $0.344V$ respectively. $A$ mixture of salts of $Bi$ and $Cu$ at unit concentration each is electrolysed at $25^{\circ }C$.
If concentration of $C{u}^{2+}$ brings down to $10^{-x}M$ before bismuth starts to deposit during electrolysis then value of $(x)$ is

Answer 1

Answer: 4

We know,
Since initially
$E_{C{u}^{2+}/Cu}^{\circ }=E_{C{u}^{2+}/Cu}^{\circ }+\frac{0.059}{2}\log \left[C{u}^{2+}\right]$
$=0.344+\log 1=0.344V$