Question

Electrode potential for Mg electrode varies according to the equation
$E _{ Mg ^{2+} / Mg }= E _{ Mg ^{2+} / Mg }^{ O }-\frac{0.059}{2} \log \frac{1}{\left[ Mg ^{2+}\right]}$
The graph of $E _{ Mg ^{2+} / Mg }$ versus $\log \left( Mg ^{2+}\right)$ is

• A.
• B.
• C.
• D.

Answer 1

Answer: (B)

The given reaction can be written as,
$E = E _{ cell }^{0}+\frac{0.059}{2} \log \left[ Mg ^{2+}\right]$
On comparing this with standard equation of straight line $y=m x+c$
We can make out that the plot of $E$ vs $\log$ and $\left[ Mg ^{2+}\right]$ will be linear with positive slope and intercept $= E _{0}$