Posted by Taz on Tuesday, June 7, 2011 at 11:15am.
There are two types of equations to balance.
1)non-redox which are balanced by trial and error.
2) redox equations which have rules that can be followed (although sometimes they can be balanced by trial and error also).
I assume you want #1. Here is a simple one.
CH4 + O2 ==> CO2 + H2O
1. I look at the equation and just start with the first element. C is 1 on the left and 1 on the right. Temporarily, at least, this one is ok for now unless something else changes it.
2. Then I look at H. There are 4 atoms on the left and I can make it 4 on the right by adding a coefficient of 2 for H2O so now the equation looks like this.
CH4 + O2 ==> CO2 + 2H2O
3. When balancing oxygen, I notice it stands by itself; therefore, I NEVER try to add O2 and try to balance it on the right. I ALWAYS count up what I need on the right, then make the one on the left the number I need. On the right I have 4 O atoms (2 from CO2 and 2 from 2H2O = 4). So I need 4 on the left and I can get that by placing a coefficient of 2 for O2 so the balanced equation reads as
CH4 + 2O2 ==> CO2 + 2H2O.
4. I ALWAYS check it to make sure it is right. I see 1 C on left and right.
I see 4 H atoms on left and right.
I see 4 O atoms on left and right. Equation is balanced.
5. How do you get more proficient at this? Practice, practice, practice.