If an element can exist in several oxidation states, it is convernient to display the reduction potentials correspondingg to the various half reactions in diagrammatic form, know as latimer diagram the latimer diagram for chlorine in acid solutio is
`CIO_(4)^(-)overset(+1.20V)toCiO_(3)^(-)overset(+1.18V)toHClO_(2)overset(+1.60V)toHClOoverset(1.67V)toCl_(2)overset(1.36V)toCl^(-)` in basic solution.
`ClO_(4)^(-)overset(0.37V)toClO_(3)^(-)overset(0.30V)toClO_(2)^(-)overset(0.68V)toClO^(-)overset(0.42V)toCl_(2)overset(1.36V)toCl^(-)` The standard potentials for two nonadjacent species can also be calculateed by using the concept that `triangleG^(@)` as an additive property but potential is not an additive property and `triangleG^(@)=-nFx^(0)`. if a given oxidation stateis a stronger oxidising agent than the next higher oxidation state, disproportionation can occur. The reverse of disproportionation is called comproportionation. The relative stabilities of the oxidation state can also be understood by drawing a graph of `triangleG^(@)//F` against oxidation state, known as frost diagram, choosing the stability of zero oxidation state arbitrarily as zero. The most stable oxidation state of a species lies lowest in the diagram, disproportionation is spontaneous if the species lies above a straight line joining its two product species.
Q. Which of the following couple have same value of potential at `pH=0` and `pH=14?`

Options

A. `(ClO_(4)^(-))/(ClO_(3)^(-))`
B. `(ClO_(2)^(-))/(Cl_(2))`
C. `(ClO_(2)^(-))/(Cl_(2))`
D. `(Cl_(2))/(Cl^(-))`

Answer

D