1. The problem statement, all variables and given/known data Calculate the number of moles of oxygen gas produced from the completely catalyzed decomposition of 6.60ml sample of a 3.5% solution of H2O2. The density of the 3.5% solution of H2O2 is 1.01 g/ml. 2. Relevant equations 2(H2O2) --> 2(H2O) + O2 p=m/v 3. The attempt at a solution I used. 1.01g/ml=m/6.6ml to get 6.1206g of the solution Multiplied 6.1206 by .035 to get .214221g H2O2 .214221g H2O2(1mol H2O2/18.016g H202)(2 mol O/2mol H2O2)(16g O/1 mol O) yields .1897g O .1897g O (1 mol O/16g O) yields .0118 mol O. This answer was rejected. I even tried .0236 since the equation shows O2, just to be sure. Wrong as well.