Balancing Equations Shortcut

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Balancing Equations Shortcut

Postby 504047082 » Sun Nov 03, 2013 11:29 am

This may be a stupid question, but is the best way to balance equations just by guess and check?

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Joined: Fri Sep 20, 2013 3:00 am

Re: Balancing Equations Shortcut

Postby powerberry » Sun Nov 03, 2013 2:41 pm

There are several techniques you can use to balance equations.

First is the cross-over method that generally works when you have different amounts of the same element on both sides in molecules. (e.g. NH3 and H2). The 3 from NH3 will become the multiple of H2 and vice versa for 2NH3 and 3H2. These can be adjusted accordingly to how many the entire equation needs.

Another good method is using fractions (especially in combustion reactions). Let's say you want to combust butane (C4H10).
Unbalanced Equation C4H10 + O2 -> H2O + CO2
Balance the carbons C4H10 + O2 -> H2O + 4CO2
Balance hydrogens C4H10 + O2 -> 5H2O + 4CO2
Balance the oxygens using a fraction C4H10 + (13/2)O2 -> 5H2O + 4CO2
then Eliminate the fractions 2C4H10 + 13O2 -> 10H2O + 8CO2.
Usually, it's easier to do it this way so you don't have to continually guess how many oxygens (or other elements) there will be.

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Re: Balancing Equations Shortcut

Postby 704628249 » Wed Dec 02, 2015 6:45 pm

Start with one element and balance it by placing coefficients. Then keep going until they all work out. Make sure that your coefficients are the smallest possible whole numbers. Ex. if you ever have 2, 2, and 4, as your coefficients, change them to 1, 1, and 2.

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