Question

A solution of H2O2 is labelled as 20 volumes .Calculate the concentration in % and normality

Answer 1

Answer :- Concentration - 6%, Normality = 3.57N

When a dilute solution of hydrogen peroxide, H₂O₂ is labelled as 20 volume, what it implies is that 1 litre of H₂O₂ solution would produce 20 litre of oxygen.

Thus may be based on the equation 2H₂O₂ ------> H₂O+ O₂

Thus we say that 20 volume of H₂O₂

gives 68/22400 x 20 =  0.06 g

which translates to 6%.

1 litre of H₂O₂ solution would produce 20 litre of oxygen.

2 x 34 = 68

∴ 22.4L of O₂ will prepare 68L of H₂O₂

Hence 20L of O₂ will prepare = 68 x 22.4 / 20 = 60.71 g of H₂O₂

Moles of H₂O₂ = Mass/ Mole Mass

Moles of H₂O₂ = 60.71/34 = 1.78 moles

Molarity = number of moles / Volume

Molarity = 1.78 / 1 = 1.78M

Equivalent Mass = Molar Mass / 2

Equivalent Mass = 34/2 = 17

Normality = Mass/(Equivalent Mass x Volume)

Normality = 60.71/(17 x 1)

Normality = 3.57N