Question

Volume strength of a sample of hydrogen peroxide is "15 vol".Its percentage strength is approximately—
(A)2.25
(B)4.55
(C)9
(D)1.12​

Answer 1

B) 4.55 %

Explanation:

Assume volume strength = x

Molar mass of H₂O₂ = 34 g/mol

2H₂O₂ = 2H₂O + O₂

From the above reaction, we can say that,

The volume strength for x Liter of oxygen = 68x/22.4

Number of moles = 68x/22.4 ÷ 34

Molarity = moles/V

              = 68x/22.4 ÷ 34/1

               = x/11.2

For 15 volume = 15/11.2 hence molarity = 1.34

Strength = 1.34 × molar mass

               = 1.34 × 34

               = 45.5 g/L = 4.55 %