Question

Among the following, the species in which the oxidation number of an element is $+6$ is :

• A. $Mn{O}_4^{-}$
• B. $Cr(CN{)}_6^{3-}$
• C. $Ni{F}_6^{2-}$
• D. $Cr{O}_{2}C{l}_2$

Answer 1

The correct option is D $Cr{O}_{2}C{l}_2$

The oxidation number of manganese in $Mn{O}_4^{-}$ is $7$.
The oxidation number of chromium in $Cr(CN{)}_6^{3-}$ is $+3$.
The oxidation number of nickel in $Ni{F}_6^{2-}$ is $+4$.
The oxidation number of chromium in $Cr{O}_{2}C{l}_2$ is $+6$.
Hence, the species in which an element has oxidation number $+6$ is $Cr{O}_{2}C{l}_2$.