Hydrazine reacts with KIO3 in presence of HCI asN2H4+IO3−+2H++Cl−⟶ICl+N2+3H2OThe equivalent masses of N2H4 and KIO3. respectively are:

O.N. of N in N2H4 is -2 which changes to 0 in N2 Hence, equivalent mass ofN2H4=molar mass2×2 =324=8O.N. of iodine changes from +5 in IO3−to +1 in ICl. Hence, equivalent mass ofKIO3 =molar mass4=2164 =54