# Question #a53c0

Apr 20, 2014

The usual procedure is to balance all atoms other than H and O; then balance O; then balance H.

Suppose you must balance the equation

CH₄ + O₂ → CO₂ + 2H₂O

Start with most complicated-looking molecule in the equation. This looks like CH₄.

1. Balance all atoms other than H and O.

1 CH₄ + O₂ → CO₂ + 2H₂O

Since we have fixed one C atom on the left, we need one C atom on the right. We put a 1 in front of the CO₂..

1 CH₄ + O₂ → 1 CO₂ + H₂O

2. Balance O.

We can’t, because both O₂ and H₂O need coefficients. So we balance H instead.

3. Balance H.

Now we have fixed 4 H atoms on the left, so we need 4 H atoms on the right. We place a 2 in front of the H₂O.

1 CH₄ + O₂ → 1 CO₂ + 2 H₂O

4. Balance O.

We have four O atoms on the right, so we need four O atoms on the left. We put a 2 in front of the O₂.

1 CH₄ + 2 O₂ → 1 CO₂ + 2 H₂O

5. Check That the Equation is Balanced.

Since every formula has a coefficient, we should now have a balanced equation. Let’s check:

On the left: 1 C; 4 H; 4 O
On the right: 1 C; 4 O; 4 H.

Our balanced equation is

CH₄ + 2O₂ → CO₂ + 2H₂O