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Saturday, December 28, 2013

HOW TO BALANCE CHEMICAL EQUATIONS WITHOUT CHEMISTRY

Every so often I have a posting on something too scientific or mathematical for normal human minds.      In 1976, for example, I spent some time at NASA's Ames Research Center devising the "ideal" system for detecting earth-sized extrasolar planets for their Search for Extraterrestrial Intelligence (SETI) program.  Frankly, I thought my concept would be a thousand times cheaper and more direct than the transit and wobble approaches selected by NASA, and still do.  Click on Planetary Abstracting Trinterferometer, with an acronym of, what else, PAT, to get a sense of just one of my impossible dreams.  NASA has now found more than a thousand extrasolar planets, but they still have no ideal goldilocks Earth equivalent.  PAT would have also provided the atmospheric composition.

A couple of years later, while teaching an Engineering-in-Training exam course, a sudden revelation came to me on "How to Balance Chemical Equations without Chemistry," so I published it in CHEMICAL ENGINEERING (pp 120,12213February 1978).  (YOU NEED TO SEND THIS TO A CHEMISTRY OR CHEMICAL ENGINEERING STUDENT!)  The problem is that courses in chemistry then (and maybe still now) teach the oxidation-number and ion-electron methods, where you need to have memorized a whole range of stuff.  Then, there is always that trial and error effort that can only work for very simple equations.

I called my invention the "neoclassical" method for balancing chemical equations, mostly because someone else almost surely must have discovered this technique before me...except I have yet to see this in print.  Given an equation (such as FeS2 + O2 = Fe2O3 + SO2), there are only three steps:
  • Enter coefficients:
    • aFeS2 +bO2 = cFe2O3 + dSO2
  • Equate elements and signs:
    • Fe:   a = 2c
    • S:   2a = d
    • O:  2b = 3c + 2d
    • (there are no signs to balance in this equation)
  • Solve the simultaneous equations, and you will get:
    • a = 4
    • b = 11
    • c = 2
    • d = 8
  • Thus, the balanced equation is:  4FeS2 + 11O2 = 2Fe2O3 + 8SO2

How much more simple can this get?

Of course, with the world wide web, all you need to do these days is to go to a site such as webqc.org/balance.php and they will do this for you.  However, until recently, you had to suffer through the effort.

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Tropical Cyclone Christine will attain hurricane strength in a couple of days and run into a desolate part of northwest Australia:


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