Calculate the e.m.f. of the following cell: \[ \text{Cu(s)} | \text{Cu}^{2+} (1M) || \text{Ag}^{+} (0.01M) | \text{Ag(s)} \] Given: \[ E^0_{\text{Cu}^{2+}/\text{Cu}} = +0.34V, \quad E^0_{\text{Ag}^{+}/\text{Ag}} = +0.80V \]
(i) Explain Kohlrausch's law. Write its applications.