1. Balancing Chemical Equations

2. What is Balancing?
Writing a chemical equation so it has the same number of reactant atoms as product atoms
Reactants = Products

3. Why do we Balance?? We must follow the Law of Conservation of Mass!
(remember? Matter can’t be created or destroyed)

4. How do you balance an equation?
Hydrogen gas reacts with chlorine gas to produce hydrochloric acid.
Write the equation first:
H2(g) + Cl2(g)  HCl
Count the atoms of each element on each side of the equation:
2 H + 2 Cl  1 H and 1 Cl

5. How do you balance an equation?
H2(g) + Cl2(g)  HCl
2 H + 2 Cl  1 H and 1 Cl
The numbers of H and Cl are NOT equal so this equation is unbalanced.

6. How do you balance an equation?
H2(g) + Cl2(g)  HCl
To balance, use coefficients
___H2(g) + ___Cl2(g)  ___HCl

7. How do you balance an equation?
___H2(g) + ___Cl2(g)  ___HCl
add a coefficient of 2
In front of HCl
___H2(g) + ___Cl2(g)  _2_HCl

8. Check Yourself: Balance the following equation:
____N2 + ____H2  ____NH3