Hydrogen Peroxide (H₂O₂) Decomposes Catalytically in the Presence of Metal $\rightarrow$

Multiple Choice

Hydrogen peroxide (H₂O₂) decomposes catalytically in the presence of metal ions and enzymes called peroxidases. You may have noticed this reaction occurring if you use a drugstore solution of hydrogen peroxide as a mouthwash or antiseptic. If a 250 mL bottle of hydrogen peroxide solution containing 3.0% H₂O₂ (by mass) completely decomposes, how many liters of oxygen gas would it generate? Assume that 1 mol of gas occupies a volume of 22.4 L and that the density of the solution is 1.0 g/mL. The reaction is
2H₂O₂(aq) $\rightarrow$ 2H₂O(l) + O₂(g)

A) 2.5 L
B) 4.9 L
C) 9.9 L
D) 7.4 L
E) 0.22 L