Air is 23.19% o2 and 75.46% n2 by weight) would be needed to burn a pound of gasoline by a reaction whereby c8h18 reacts with o2 to form co2 and h2o?

Approximately pounds.

Start by balancing the equation for the complete combustion of octane in oxygen:

Thus it would take molecules of oxygen to completely react with molecules of octane. Oxygen and octane thus react at a ratio of

to

Given the molar mass of the species:

The mass ratio between the two species when the combustion proceeds to completion would thus equal:

to

It would thus take

to combust completely one pound of octane.

Apply the mass ratio stated in the question:

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