What is the balanced equation for combustion of octane?

My teacher asked me how many Liters of carbon dioxide does a van spew if the carburator consumes 5.67L of Gas (C₈H₁₈), without giving me the rest of the equation. Is 2 C₈H₁₈ + 25 O₂ = 18 H₂O + 16 CO₂ correct?
Yancarlo Mondriguez

Yes, Yancarlo, you have it right. Completely burning a fuel that contains C produces CO₂(g); if the fuel contains H, H₂O(l) is also produced. Any oxygen that was present in the fuel will end up in the carbon dioxide and water. Other elements in the fuel can produce additional products. For example, S in the fuel produces SO₂(g).

When balancing the equation, you have to add enough O₂ to the reactant side to completely balance the oxygens in the CO₂ and H₂O products.

For more about the individual steps used, see 10 tips for balancing simple equations.

Author: Fred Senese senese@antoine.frostburg.edu

Copyright © 1997-2010 by Fred Senese
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Last Revised 02/23/18.URL: http://antoine.frostburg.edu/chem/senese/101/reactions/faq/equation-octane-combustion.shtml