I am extremely confused on how to balance a chemical equation. I have an exam tomorrow and I'm lost.

In the book it says
Chemical Equation: CH4 + O2 > CO2 + H2O

Balanced Chemical Equation: CH2 + 2O2 > CO2 + 2H2O

How did this happen?

Thanks.

Oh and what is the main rule for equilibrium and reaction rates?

I know that there are factors for affecting the reaction rates but I'm still so confused.

5 answers

the C balances as written, since there is one on each side. That leaves you with

CH4 + ?O2 > CO2 + ?H2O

you have 4H on the left, so you will need 2H2O on the right. That gives

CH4 + ?O2 > CO2 + 2H2O

That balances the C and H, so now you need 4O on the left, which is 2O2

CH4 + 2O2 > CO2 + 2H2O

Usually I start by balancing the atoms that appear the least, letting the others jiggle until they can work themselves out. This one was rather easy, since there were no odd atoms clogging things up. Lots of examples online via google.
Thank you so much :) So basically I just have to make sure that the atoms have the same number on each side.
Yes, exactly.
Fin fit
My exam was so easy! Thank youuuuuuuuuuuu