The strength of 11.2 volume solution of H₂O₂ is: [Given that molar mass of H = 1 g mol⁻¹ and O = 16 g mol⁻¹]

Correct option is B. 3.4

11.2 volume solution of H₂O₂ means that 1 volume of H₂O₂ solution gives 11.2 volumes of O₂ at STP.

The balanced chemical equation for the decomposition of H₂O₂ is:
2H₂O₂ → 2H₂O + O₂

From the stoichiometry, 2 moles of H₂O₂ produce 1 mole of O₂.

At STP, 1 mole of any gas occupies 22.4 L.

Let's consider 1 L of 11.2 volume H₂O₂ solution. It will produce 11.2 L of O₂ at STP.

Number of moles of O₂ produced = Volume of O₂ at STP / Molar volume at STP = 11.2 L / 22.4 L/mol = 0.5 mol

From the stoichiometry, 2 moles of H₂O₂ produce 1 mole of O₂.
Therefore, moles of H₂O₂ in 1 L solution = 2 × moles of O₂ = 2 × 0.5 mol = 1 mol

Mass of H₂O₂ in 1 L solution = moles × molar mass = 1 mol × (2 × 1 + 2 × 16) g/mol = 34 g

Strength of H₂O₂ solution = (Mass of H₂O₂ / Volume of solution) × 100 = (34 g / 1 L) × 100 = 3.4 %