Determine the potential for the cell :
`Pt|Fe^(2), Fe^(3+)||Cr_(2)O_(7)^(2-), Cr^(3+), H^(+)|Pt`
in which `[Fe^(2+)]` and `[Fe^(3+)]` are 0.5 M and 0.75 M respectively and `[Cr_(2)O_(7)^(2-)], [Cr^(3+)]` and `[H^(+)]` are 2M, 4 M and 1M respectively. Given :
`{:(Fe^(3+)+e^(-) rarr Fe^(2+),,E^(@)=0.770"volt"),(14H^(+)+6e^(-)+Cr_(2)O_(7)^(2-) rarr 2Cr^(3+)+7H_(2)O,,E^(@)=1.35" volt"):}`

Answer

0.56 volt