What are the rules in balancing chemical equations?

Answer:
1) Identify all elements
2) Obtain element counts
3) Balance
a) change one coefficient at a time
b) update element counts
c) repeat until balanced

4) double check balance

EXAMPLES:
H2 + O2 --> H2O
"which equals"
2H2 + O2 --> 2H2O

HNO3 + Mg(OH)2 --> Mg(NO3)2 + H2O
"which equals"
2HNO3 + Mg(OH)2 --> Mg(NO3)2 + 2H2O
First answer by MegaDjCandy. Last edit by MegaDjCandy. Contributor trust: 1 [recommend contributor recommended]. Question popularity: 2 [recommend question].