Balancing Chemical Equations

Balancing Chemical Equations

• A balanced chemical equation has the same number of atoms for each element before and after a reaction.

• We balance a chemical equation by placing the correct coefficient before each element or compound in an equation. Do not change or add subscripts.

The Chemical Equation

Six Steps to Balancing Equations

• Follow these 6 steps to balance a chemical equation:

H₂ + O₂ –> H₂O

1. Count atoms of each element

Element # atoms before # atoms after balanced

H (hydrogen) 2 2 yes

O (oxygen) 2 1 NO

2. Balance the first element

• We can begin to balance this equation by adding a coefficient to balance the oxygen as follows:

H₂ + O₂ –> 2H₂O

3. Re-count atoms of each element

Element # atoms before # atoms after balanced

O (oxygen) 2 2 yes

H (hydrogen) 2 4 NO

4. Balance the next element

• We can finish balancing this equation by adding a coefficient to balance the hydrogen as follows:

2H₂ + O₂ –> 2H₂O

5. Re-count each element

Element # atoms before # atoms after balanced

H (hydrogen) 4 4 yes

O (oxygen) 2 2 yes

6. Repeat until balanced

• Continue to balance and re-count until all elements are equal before and after a reaction.