1
$\begingroup$

Which species can act as an oxidizing agent but not as a reducing agent?

(A) $\ce{Cl2}$
(B) $\ce{Cl-}$
(C) $\ce{ClO2-}$
(D) $\ce{ClO4-}$

I thought the answer was A because if $\ce{Cl}$ is reduced, it becomes very stable with a full octet and therefore cannot be the reducing agent; however, according to the 2007 Chemistry Olympiad answer key, the answer is D. Why is that?

$\endgroup$
1
  • 2
    $\begingroup$ There is a very simple and well-known reaction in which Cl2 acts as a reducing agent. Then again, I believe perchlorate also would act that way if confronted with elemental fluorine or something. The question is badly posed. I guess the implication was that chlorine is already in its topmost oxidation state, hence... $\endgroup$ Dec 23, 2016 at 5:44

1 Answer 1

5
$\begingroup$

For a species to act as a reducing agent, it should have the ability to get oxidised. Any element in its highest oxidation state, cannot oxidise anymore, and can hence not act as a reducing agent. $\ce{ClO4-}$ has $\ce{Cl}$ in $+7$ oxidation state, and cannot have a higher oxidation state, and hence cannot act as a reducing agent.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.