One ecologically important equilibrium is that between carbonate and hydrogen carbonate ions in natural water. This standard Gibb's energies of formation of `CO_(3)^(-2)(aq)` and `HCO_(3)^(Theta)(aq)` are `-527.8 kJ mol^(-1)` and `-586.8 kJ mol^(-1)` respectively.
For water,
`2H_(2)O(l) +2e^(Theta) rarr H_(2)(g) +2OH^(Theta)(aq) , E_(RP)^(Theta) =- 0.83 V`
`2H_(2)O rarr O_(2) +4H^(+) +4e^(Theta), E_(OX)^(Theta) = - 1.23V`
Calculate the potential of a cell of `pH = 7` in which the cell reaction is-
`Na_(2)CO_(3)(aq) +H_(2)O(l) rarr NaHCO_(3)(aq).+NaOH(aq)`

Options

A. `-0.22` volt
B. `+0.193` volt
C. `-0.0135` volt
D. `+0.41` volt

Answer

B