`0.3 g` of an oxalate salts was dissolved in `100 mL` solution. The solution required `90 mL` of `N//20 KMnO_(4)` for complete oxidation. The `%` of oxalate ion in salt is:

Options

A. `3.3%`
B. `66%`
C. `70%`
D. `40%`

Answer

B

Explanation

Meq. Of `KMnO_(4)=M` eq. of `C_(2)O_(4)^(-2)`
`90xx(1)/(2)=100xxN_(C_(2)O_(4)^(2-))`
Mmole of oxalate `=(9)/(2xx2)=(9)/(4)`
Weight of oxalate `=(9)/(4)xx88xx10^(-3)=22xx9xx10^(-3)`
`198xx10^(-3)`
`%C_(2)O_(4)^(-2)=(.198)/(.300)xx100=66%`