A 0.46 g sample of `As_(2)O_(3)` required 25.0 " mL of " `KMnO_(4)` solution for its titration. The molarity of `KMnO_(4)` solution for its titration. The molarity of `KMnO_(3)` solution is

Options

A. 0.016
B. 0.074
C. 0.032
D. 0.128

Answer

B

Explanation

`As_(2)O_(3)to2AsO_(4)^(3-)+4e^(-)`
`5e^(-)+MnO_(4)^(ɵ)toMn^(2+)`
`(Ew of As_(2)O_(3)=(2xx75+3xx16)/(4)=(198)/(4))`
`As_(2)O_(3)-=MnO_(4)^(ɵ)`
`mEq-=mEq`
`((0.46)/((198)/(4)))xx10^(3)-=25xxN`
`N=0.037`
`M_(KMnO_(4))=(N)/(5)=(0.037)/(5)=0.074`