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Given that, Co^(3+) +e^(-)rarr Co^(2+) E...

Given that, `Co^(3+) +e^(-)rarr Co^(2+) E^(@) = +1.82 V`
`2H_(2)O rarr O_(2) +4H^(+) +4e^(-), E^(@) =- 1.23 V`.
Explain why `Co^(3+)` is not stable in aqueous solutions.

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The potential `(Co^(3+)|Co)` is large and sufficient to oxidize water . Therefore , Co(III) in aqueous solution has a tendency to change to Co(II) . Hence Co(III) is unstable in aqueous solution .
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