All the following species are strong oxidizing agents. Their strength as oxidizing agents in acidic solution is such that

Options

A. `S_(2)O_(8)^(2-) gt Cr_(2)O_(7)^(2-) gt MnO_(4)^(-)`
B. `MnO_(4)^(-) gt Cr_(2)O_(7)^(2-) gt S_(2)O_(8)^(2-)`
C. `S_(2)O_(8)^(2-) gt MnO_(4)^(-) gt Cr_(2)O_(7)^(2-)`
D. `Cr_(2)O_(7)^(2-) gt S_(2)O_(8)^(2-) gt MnO_(4)^(-)`

Answer

C

Explanation

`S_(2)O_(8)^(2-)- + 2e to 2SO_(4)^(2-) E^(@) = +2.05 V`
`MnO_(4), + 8H^(+)+5e^(-) to Mn^(2+) 4H_(2)O E^(@) = +1.51 V`
`Cr_(2)O_(7)^(2-) + 14H^(+)+6e^(-) to 2Cr^(3+) + 7H_(2)O E^(@) = +1.33 V`
The specie which has the most positive reduction potential is the strongest oxidizing agent.