What is the concentration of 3.0% H2O2 in molar units?

Answer 1

Assuming it is 3.0% (mass/volume), this means you have 3.0 g H₂O₂ in 100 mls of solution.

Molar mass H₂O₂ = 34.0 g / mole

3.0 g H₂O₂ / 100 mls x 1 mol H₂O₂ / 34.0 g x 1000 mls / L = 0.88 mol / L = 0.88 M H₂O₂