A sample of hydrazine sulphate `(N_(2)H_(6)SO_(4))` was dissolved in `100 mL` water. `10 mL` of this solution was reacted with excess of `FeCl_(3)` solution and warmed to complete the reaction. Ferrous ions formed were estimated and it required `20 mL` of `M//50 KMnO_(4)` solutions. Estimate the amount of hudrazine sulphate in one litre of solution.
Given `4Fe^(3+)+N_(2)H_(4)rarrN_(2)+4Fe^(2+)+4H^(+)`
`MnO_(4)^(-)+5Fe^(2+)+8H^(+)rarrMn^(2+)+5Fe^(3+)+4H_(2)O`

Explanation

20 " mL of " `(M)/(50)KMnO_4`
`=(20)/(50)m" mol of "KMnO_4`
`=(2)/(5)xx5m" Eq of "KMnO_4`
`=2 m" Eq of "Fe^(2+)=2 m" mol of "Fe^(2+)`
`=(2)/(4)m" mol of "N_2H_4`
`=0.5xx10^(-3)" mol of "N_2H_6SO_4`
`=0.5xx10^(-3)xx130g of N_2H_6SO_4`
`=0.065 g i n 10 mL`
`=6.5 g i n 1L=6.5gL^(-1)`