Balancing equations
To balance equations on your own, follow these simple rules:
- Check that all the formulae in the equation are correct.
- Deal with only one element at a time.
- Balancing is adding BIG numbers. You cannot change any of the small numbers in a chemical formula. If balancing is required, put the number in front of the substance.
- Check each element again and repeat step 3 again if needed.
Example
\({C_4}{H_8} + {O_2} \to C{O_2} + {H_2}O\)
This equation is unbalanced. There are four carbon atoms on the left hand side and only one on the right. To balance the carbon, add a big '4' in front of the carbon dioxide.
\({C_4}{H_8} + {O_2} \to 4C{O_2} + {H_2}O\)
Next, to balance the hydrogen. We have 8 atoms of hydrogen on the left hand side in C 4H8and only 2 on the right hand side. To balance the hydrogen atoms, add a big '4' in front of H2O.
\({C_4}{H_8} + {O_2} \to 4C{O_2} + 4{H_2}O\)
We’re not finished yet. Now that the carbon and hydrogen have been balanced, we only have to balance the oxygen. We have 2 atoms of oxygen on the left, but in total on the right (taking into account what we have balanced already) we have 12 oxygen atoms. This can be balanced by adding a big '6' in front of the diatomic oxygen molecule on the left hand side.
The balanced equation will be:
\({C_4}{H_8} + 6{O_2} \to 4C{O_2} + 4{H_2}O\)