When the equation KClO 3 ( s ) → KCl( s ) + O 2 ( g ) is balanced, the coefficient of KClO 3 is .
4
2
3
1

Explanation:

Often, the best way to start is to balance all atoms other than O and H, then balance O, then balance H.

1. Put a 1 in front of the most complicated-looking formula (KClO₃):

1KClO₃ ⟶ 2KCl + O₂

2. Balance K:

We have fixed 1 K on the left. We need 1 K on the right. Put a 1 in front of KCl.

1KClO₃ ⟶ 1KCl + O₂

3. Balance Cl:

Done.

4. Balance O:

We have fixed 3 O on the left. We need 3O on the right. Uh, oh. Fractions.

Double every underlined coefficient

2KClO₃ ⟶ 3KCl + O₂

Now, we have 6 O on the left. we can put a 3 in front of O₂.

2KClO₃ ⟶ 3KCl + 3O₂

Every formula now has a coefficient. The equation should be balanced.

5. Check that atoms balance:

The equation  is now balanced.

every chemical equation adheres to the law of conservation of mass, which states that matter cannot be created or destroyed. therefore, there must be the same number of atoms of each element on each side of a chemical equation.