A solution of $\mathrm{Fe^{3+}}$ is titrated potentiometrically using $\mathrm{Ce^{3+}}$ solution at $25\,{}^{\circ}\mathrm{C}$. The emf (in V) of the redox system thus formed when, (i) $50\%$ of $\mathrm{Fe^{3+}}$ and (ii) $80\%$ of $\mathrm{Fe^{3+}}$ are titrated, would respectively be (Given $E^{o}_{\mathrm{Fe^{3+}/Fe^{2+}}}=0.77\,V$, $\log 2=0.301$)