So heres the problem I am faced with... dum dum dummmm So first I figured that there will be 30.6g of hydrogen peroxide. Then I figured that there are 0.4498 moles of O2. Then using the ideal gas law... V=nRT/P I got ((0.4498)(0.08206)(27+273.15))/(746/760) = 11.3 Liters of O2 But supposedly im wrong. Where did I go so horribly horribly wrong? Oops, and i just punched in 22.6 Liters and it says I'm right.... so where did I divide by 2 where I shouldn't have?