The pair of the compounds in which both the metals are in the highest possible oxidation state is

Options

A. `[Fe(CN)_(6)]^(3-), [Co(CN)_(6)]^(3-)`
B. `CrO_(2)Cl_(2), MnO_(4)^(-)`
C. `TiO_(3), MnO_(2)`
D. `[Co(CN)_(6)]^(3-), MnO_(2)`

Answer

B

Explanation

In case of neutral molecules, the algebraic sum of the oxidation number of all the atoms present in the molecules is zero. For complex ion , the algebraic sum of oxidation number of all atoms is equal to net charge on the ion.
Let the oxidation number of Cr in `CrO_(2)Cl_(2)` and oxidation number of Mn in `MnO_(4)^(-)` are x and y respectively.
`CrO_(2)Cl_(2)`
`MnO_(4)^(-)`
`x+2(-2)+2(-1) = 0`
`x-4-2=0`
`x-6 = 0`
x = 6
`y+4(-2) = -1`
`y-8 = -1`
`y = -1+8`
y = 7