Question

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

• A.
• B.
• C.
• D.

Answer 1

Answer: (B)

$E_{Mg^{2+}/Mg} = E^{\circ}_{Mg^{2+}/Mg} + \frac{0.059}{2}$ log $\left[Mg^{2+}\right]$
Compare this equation with the equation of straight line $y = mx + c$
The graph of $E_{Mg^{2+}}/Mg$ vs log $\left[Mg^{2+}\right]$ is a is a straight line with a positive slope and intercept $ =E^{\circ}_{Mg^{2+}/Mg}$