Question

`3.92 g` of ferrous ammonium sulphate crystals are dissolved in `100 ml` of water, `20 ml` of this solution requires `18 ml` of `KMnO_(4)` during titration for complete oxidation. The weight of `KMnO_(4)` present in one litre of the solution is
A. (a)` 3.476 g`
B. (b)` 12.38 g`
C. (c )` 34.76 g`
D. (d)` 1.238 g`

Answer 1

Correct Answer - A
`KMnO_(4)`= Mohr salt
`(M_(1)V_(1))/1=(M_(2)V_(2))/5`
`=[W/(MxxV)xx1000]xxV_(2)/5`
`[(Wxx1000)/(58xx1000)]xx18= (3.92xx1000)/(392xx1000)xx20/5 W=3.476 g//L`.