Answer
+0.38 V
Work Step by Step
$pH= -\log [H^{+}]=7.8$
$\implies [dilute\, solution]=10^{-7.8}$
$E_{cell}= E^{\circ}_{cell}-\frac{0.0592}{n}\log\frac{[dilute\, solution]}{[concentrated\, solution]}$
$=0-\frac{0.0592}{1}\log\frac{10^{-7.8}}{0.05}$
$=+0.38\,V$
