# How do you balance a chemical equation? For example: H_2 + O_2 = H_2O

May 29, 2016

$\text{Garbage in equals garbage out!}$

#### Explanation:

In every chemical reaction mass is conserved. If I start with $10 \cdot g$ of reactant, at most I am going to $10 \cdot g$ of product. In practice, I am not even going to get that, because losses invariably occur on handling.

${H}_{2} \left(g\right) + \frac{1}{2} {O}_{2} \left(g\right) \rightarrow {H}_{2} O \left(l\right)$
Here is a similar question. Methane, $C {H}_{4}$, burns on a gas cooker. It combines with oxygen, ${O}_{2}$, to give carbon dioxide, $C {O}_{2}$, and water, ${H}_{2} O$.
$\text{Methane + oxygen "rarr" carbon dioxide + water}$
Can you propose a balanced symbol equation? What about for ehane, ${H}_{3} C - C {H}_{3}$?