One would need 3498.93498.9 grams of O_2O2 for this particular combustion.
The combustion reaction can be written as follows
C_9H_20 + 14O_2 -> 9CO_2 + 10H_2OC9H20+14O2→9CO2+10H2O
we can see that 11 mole of nonane needs 1414 moles of O_2O2 for the combustion reaction; from m_(C_9H_20)mC9H20 = 11 kg, one can solve for the number of moles of nonane
n_(C_9H_20) = (1000g)/(128 g/(mol)) = 7.81 nC9H20=1000g128gmol=7.81 moles
(using 1 kg1kg = 1000 grams1000grams and knowing the molar mass of nonane to be 128g/(mol)128gmol );
Therefore, the number of O_2O2 moles will be
n_(O_2) = 14 * 7.81 = 109.34nO2=14⋅7.81=109.34 moles
The mass of O_2O2 yields
m_(O_2) = 109.34 * 32 = 3498.9mO2=109.34⋅32=3498.9 grams
IF you need the quantity of AIRAIR, just remember that air contains 20.95% O_220.95%O2 , 78.09% N78.09%N, and a little under 1%1% other gasses (Ar, CO_2Ar,CO2,and others).