Question

Select the strongest oxidant oxoanion and weakest oxidant oxanion among the following:

$V{O}_4^{3-},Cr{O}_4^{2-},Mn{O}_4^{2-},Fe{O}_4^{2-}$

• A. Strongest : $Fe{O}_4^{2-}$; weakest : $V{O}_4^{3-}$
• B. Strongest : $V{O}_4^{3-}$ ; weakest : $Fe{O}_4^{2-}$
• C. Both are equally strong
• D. None of these

Answer 1

The correct option is A Strongest : $Fe{O}_4^{2-}$; weakest : $V{O}_4^{3-}$

The oxidation numbers of the central metal atom in $V{O}_4^{3-},Cr{O}_4^{2-},Mn{O}_4^{2-},Fe{O}_4^{2-}$ are $+5,:+6,+6$ and $+6$ respectively.
Lower is the oxidation number, weaker will be the oxidant oxoanion.
Thus, $V{O}_4^{3-}$ is the weakest oxidant oxoanion as it has least oxidation number.
$Fe{O}_4^{2-}$ is the strongest oxidant oxoanion as it has highest oxidation number as well as highest effective nuclear charge.