Question

what is volume strength and how to calculate it?​

Answer 1

Volume or percentage strength of hydrogen peroxide is a term to express concentration of H2O2 in terms of volumes of oxygen gas based on its decomposition to form water and oxygen.

2H2O2 →Δ 2 H2O + O2

Conversion of molarity to volume strength

Suppose we have a solution of M moles of H2O2 in 1L solution

From the reaction stoichiometry, 2 moles of H2O2 gives 1mol of oxygen or 22.4L at S.T.P

1mole of H2O2 = 11.2 L of O2

M mole of H2O2 = 11.2 x M L of O2

1L of H2O2 gives 11.2 x M L of O2

Vol strength of H2O2 = 11.2 x M

In terms of Normality, N

n factor for H2O2 is 2

N = M x n or N = M x 2

Volume strength = 11.2 M = 11.2 x N/2 = 5.6 N