Chemical Forums
Chemistry Forums for Students => High School Chemistry Forum => Topic started by: gogz on March 04, 2018, 12:51:06 PM
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Hi there, I'm a new user and I study mechanical engineering. As part of my coursework I have been asked to solve a stoichiometric equation with regards to 80% methane and 20% ethane. I have tried doing it myself but can't seem to get it. The equation is as follows:
CH4+C2H6+(O2+3.76N2)
Thank you for your time
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What do you think could happen? Perhaps write the equation as 4 methane + 1 ethane + oxygen and nitrogen (assuming this percentage is by moles, or volume)?
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In general (and especially for someone not used to such tricks) it is better to calculate stoichiometry for individual reactions and then to sum the results, then to work with reactions that are in fact sum of independent reactions. While the latter works, it is much more difficult to modify and generalize (and in no way faster).
But if you are asked to do it the hard way you have to express the composition using stoichiometric coefficients, sjb points you in the right direction.
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Also, the problem will have to tell you the products, especially for those reactants. The reaction of hydrocarbons and oxygen can be guessed at, but the addition of nitrogen as a reactant can give several different oxides of nitrogen.
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Maybe the nitrogen oxides can be neglected? The tiny amounts are all-important for our health, but to balance the equation, they matter little.
The advantage of nitrogen is that it cools the flame (provided it's a flame), so the combustion products are simpler. With pure oxygen, the proportions of monoxide, hydrogen, formaldehyde... can't be decided by hand. Air instead makes things manageable.
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What you present is not an equation. Kindly review and clarify.