Question

The pair of compounds having metals in their highest oxidation state is

• A. $Mn{O}_2,FeC{l}_3$
• B. ${\left[Mn{O}_4\right]}^{-},Cr{O}_{2}C{l}_2$
• C. ${\left[Fe(CN{)}_6\right]}^{3-},\left[Co(CN{)}_3\right]$
• D. ${\left[NiC{l}_4\right]}^{2-},{\left[CoC{l}_4\right]}^{-}$

Answer 1

Answer: (B)

(a) In $Mn{O}_2,FeC{l}_3$ oxidation states of $Mn$ and $Fe$ are $+4$ and $+3$ respectively.
(b) In ${\left(Mn{O}_4\right)}^{-},Cr{O}_{2}C{l}_2$ oxidation states of $Mn$ and $Cr$ are $+7$ and $+6$ respectively.
(c) In ${\left[Fe(CN{)}_6\right]}^{3-},\left[Co(CN{)}_3\right]$ oxidation states of $Fe$ and $Co$ are $+3$ and $+3$ respectively.
(d) ${\left[NiC{l}_4\right]}^{2-},{\left[CoC{l}_4\right]}^{-}$oxidation states of $Ni$ and Co are $+2$ and $+3$ respectively.