[boogaaaaa]

For my experiment my group and I decided to demonstrate a combustion reaction. The experiment basically consists of pouring different types of alcohol into a 5-gallon bottle and lighting it. I'm trying to calculate the ideal ratio in which both the fuel and the oxygenl will be completely consumed.

First off, I calculated the following:
density of O2 = 1.33g/L (STP)
5gallon = 18.9L
since air is 20.947% oxygen, the volume of O2 is 3.97L
mass of O2 (density x volume) = 5.3g
mol of O2 (mass/molar mass) = 0.16562
Density of methanol = .79g/ml
Density of propanol = .79g/ml


methanol:

2CH3OH(l) + 3O2(g) --> 2CO2(g) + 4H2O(l)
0.165625mol O2 x 2mol methanol/3mol O2 = .11 mol methanol

m=(n)(molar mass)
m=(.11)(32.05)
m=3.5g

v=mass/Density
v= 3.5/0.79
v= 4.43mL

4.43 ml of methanol required?

2-propanol

2C3H7OH + 9O2 --> 6CO2 + 8H2O
0.165625mol O2 x 2mol propanol/9mol O2 = .0368 mol methanol
m=(n)(M)
m=(.0368)(60.11)
m=2.21g

v=m/D
v=2.21/.79
v=2.8mL

2.8mL of propanol required?

These numbers seem a bit small to me, can someone verify if my work is correct?