Consider the hypothetical reaction occuring at T = 298 K

${\mathrm{Cl}}_2\left(\mathrm{g}\right)+2{\mathrm{Br}}^{-}\left(\mathrm{aq}\right)\to 2{\mathrm{Cl}}^{-}\left(\mathrm{aq}\right)+{\mathrm{Br}}_2(\mathrm{aq}.)$

The emf of the cell, when $\left[{\mathrm{Cl}}^{-}\right]=\left[{\mathrm{Br}}_2\right]=\left[{\mathrm{Br}}^{-}\right]=0.01\mathrm{M}$ and ${\mathrm{Cl}}_2$ gas is at 1 atm pressure, will be: 

(${\mathrm{E}}^{\mathrm{o}}$ for the above reaction is = 0.29 volt)