Chemistry · Different methods for expressing the concentration of solution: molality, molarity, mole fraction, percentage (by volume and mass both)

The volume strength of (w/v) solution of is :

The volume strength of \( 15 \% \) (w/v) solution of \( \boldsymbol{H}_{2} \boldsymbol{O}_{2} \) is :

  • A. 50
  • B. 4.94
  • C. 494
  • D. 0.494

Step-by-step solution

15% (w/v) H2O2 means 15 g per 100 mL, i.e., 150 g/L. Molar mass H2O2 = 34 g/mol, so molarity = 150/34 ≈ 4.4118 M. Decomposition: 2H2O2 → 2H2O + O2, so 1 mol H2O2 yields 0.5 mol O2. At STP, 0.5 mol O2 occupies 11.2 L. Thus volume strength = molarity × 11.2 = 4.4118 × 11.2 = 49.41 L O2 per L solution, approximately 50.
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