How many mililiters of 20 volume of `H_2O_2` solution is needed to react completely with 500mL of acidified 1N `KMnO_4` solution?

Options

A. 224
B. 280
C. 140
D. 56

Answer

C

Explanation

Given
Normality of `KMnO_(4) (N_(1)) = 1M`
Volume of `KMnO_(4) (V_(1)) = 500 mL`
Normality of `H_(2) O_(2) (N_(2)) = (vol. of O_(2) at NTP )/(5 . 6 (eq."mass")) = (20)/(5 . 6)`
`(N_(2)) = 3 . 5 gt N`
To find : Volume of `H_(2) O_(2) (V_(2))`
`:. N_(1)V_(1) = N_(2) V_(2)`
`1 xx 500 = 3 . 57 xx V_(2)`
`:. V_(2) = (500)/(3.57) = 140 mL`
Hence,
Volume of `H_(2) O_(2) ` used = 140 mL