5 litres of a solution of H2O2 with x N strength is diluted to 5.5 litres.
The normality changes to 5x5.5 N.
The normality of the solution and the concentration in g/L are related by the expression, Normality=Concentration in g/LEquivalent mass
Concentration in g/L=Normality×Equivalent mass
The mass of H2O2 present in 1 L of H2O2 solution is 5x5.5×17.
The equivalent mass of H2O2 is 17.
Hence, the mass of H2O2 present in 5.5 L of H2O2 solution is 5.5L×5x5.5×17......(1)
At NTP, 68 g of H2O2 gives 22400 mL of oxygen.
Hence, 28 litres of oxygen is obtained from 6822400×228000=85g of H2O2.
Substitute this in equation (1).
5.5L×5x5.5×17=85
Hence, x=1.
Thus, the strength of H2O2 solution is 1 N.