3. Chemical Reactions
Stoichiometry
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ANSWERS OPTIONS
A
428.19 mg
B
469.27 mg
C
495.45 mg
D
521.33 mg
Bleaching of hair usually involves the reaction of hydrogen peroxide (H2O2) with the melanin (C18H10N2O4) in hair. As the bleaching solution is rubbed to hair, melanin is oxidized by hydrogen peroxide: C18H10N2O4 + 34 H2O2 → 2 NH3 + 36 H2O + 18 CO2. A bleaching solution contains 9% H2O2 by mass. If 20 g of the bleaching solution is used, calculate the mass (in mg) of melanin that is oxidized.