A sample of hydrazine sulphate ( ) was dissolved in 100 mL water

CHEMISTRY · Subjective · A Level · Chemistry · Oxidation, reduction and redox reactions · Oxidation, reduction and redox reactions

Problem

A sample of hydrazine sulphate (

\text{N}_2\text{H}_6\text{SO}_4

) was dissolved in 100 mL water. 10 mL of this solution was reacted with excess of

\text{FeCl}_3

solution and warmed to complete the reaction. Ferrous ions formed were estimated and it required 20 mL of

M/50\ \text{KMnO}_4

solution. Estimate the mass of hydrazine sulphate in one litre of solution: Given,

4\text{Fe}^{3+} + \text{N}_2\text{H}_4 \longrightarrow \text{N}_2 + 4\text{Fe}^{2+} + 4\text{H}^+

\text{MnO}_4^- + 5\text{Fe}^{2+} + 8\text{H}^+ \longrightarrow \text{Mn}^{2+} + 5\text{Fe}^{3+} + 4\text{H}_2\text{O}