What is the order of relative basic strength of `ClO_(2)^(-),ClO_(3)^(-),ClO_(4)^(-)?`

Options

A. `ClO_(2)^(-)gtClO_(3)^(-)gtClO_(4)^(-)`
B. `ClO_(3)^(-)gtClO_(2)^(-)gtClO_(4)^(-)`
C. `ClO_(4)^(-)gtClO_(2)^(-)gtClO_(3)^(-)`
D. `ClO_(2)^(-)gtClO_(4)^(-)gtClO_(3)^(-)`

Answer

A

Explanation

More be the oxidation state of central atom (i.e. Cl-atom) , more is the acidic nature of the species and lesser will be the basic strength . As , oxidation number of :
` Cl " in " ClO_(2)^(-) to x - 4 = - 1`
`x = + 3 `
Cl in ` ClO^(-) _(4) to x- 8 = - 1`
x = + 7
Thus , order of acidic nature is
` ClO_(4)^(-) gt ClO_(3)^(-) gt ClO_(2)^(-)`
and order for basic strength is
` ClO_(2)^(-) gt ClO_(3)^(-) gt ClO_(4)^(-)` .
Alternate method
The more be the oxygen atom in the given species, the more is the dispersion of electrons from Cl-atoms , which decreases the basic strength .
` becacuse ClO_(2)^(-)` has only two oxygen atoms while ` ClO_(4)^(-)` has four oxygen atoms , Thus , order of basic strength is
` ClO_(2)^(-) gt ClO_(3)^(-) gt ClO_(4)^(-)`
Hence, option (a) is the correct answer.