1. Balancing Chemical Equations.

5. Balancing Chemical Equations
Some useful tips:
1. List the number of each atoms for the right side and the left side.
2. Find an element that is in only one compound on the left side and in only one compound on the right side, and balance that element first.
Depending on the elements present in the reaction, start with an atom other than Hydrogen and Oxygen, because they tend to appear more than once.
3. Start by looking for the compound that has the most number of subscripts on its elements on one side; then balance the elements appearing on the other side of that reaction first.
4. When polyatomic ions like (PO43- etc.) appears as the same on both sides of the reaction, treat the polyatomic ion as a group of atoms.
5. When an atom like Oxygen appears just once on one side in the form of 02, but appears on the other side more than once; it’s easier to balance the side it appears more than once first before balancing the side it appears once. (Example is in combustion reactions of hydrocarbons).

26. phet.colorado.edu In addition to above practice:
Check out this free online simulation:
phet.colorado.edu
(by the University of Colorado).
Search for: Balancing chemical equation
You can practice Balancing equations with lots of balancing games.