# How do you balance CH_4 + O_2 -> CO_2 + H_2O?

Feb 8, 2016

$\text{Garbage out MUST equal GARBAGE in.}$

#### Explanation:

$C {H}_{4} \left(g\right) + {O}_{2} \left(g\right) \rightarrow C {O}_{2} \left(g\right) + {H}_{2} O \left(g\right)$ $\text{UNBALANCED}$

The given reaction is balanced with respect to carbon, but IMBALANCED with respect to hydrogen and oxygen. Balance the hydrogen FIRST, and then the oxygen.

$C {H}_{4} \left(g\right) + 2 {O}_{2} \left(g\right) \rightarrow C {O}_{2} \left(g\right) + 2 {H}_{2} O \left(g\right)$ $\text{BALANCED}$

Typically, when you balance these combustion reactions (which are of course formal oxidation reduction reactions), you follow the order, (i) balance the carbons, and then (ii) the hydrogens, and then (iii) the oxygens.