Problem: We desire to learn how much oxygen is needed to completely consume a certain quantity of propane gas.
Our hydrocarbon and oxygen combustion question follows the basic reaction path,
C₃H₈ + 5 O₂ → 4 H₂O + 3 CO₂
If we have the following conditions:
Temperature = 75 Celsius (348 Kelvin)
Pressure = 720 mm/ 760 mm = 0.95 atmospheres
Moles propane = 40.8 grams / 44.1 grams molecular weight = 0.93 moles
How Much Oxygen to Burn the Propane?
What volume of oxygen is needed to accomplish the burning of the 0.93 moles of the hydrocarbon?
5 times 0.93 = 4.65 moles oxygen
The ideal gas law reads:
PV = nRT
where P= pressure, V= volume, n= number of moles and T is degrees Kelvin.
0.95 atmospheres (V liters) = 4.65 (0.082 liter-atmospheres per mole per degree Kelvin) (348 degrees Kelvin)
V = 4.65 (348) / 0.95 = 1700
The answer is: To burn the hydrocarbon, 1700 liters of oxygen gas is needed.
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