1. Recap: Drip Drop Lab
WCHS Chemistry

3. H Cl H O Na Na O Cl H H O O S O S H H H O Na O O O O O O O H H H O Na Na Na H H

4. 3 7 45 3 14 30 9 42
120

5. H H H H H H Fe O O Na Cl Fe O O Fe O O Na Cl Fe Fe O O Na Cl Fe O Ca OBr O O P O O N O Mg O N O Ca O P O O O O O O O O Ca O O Na O Br N Mg O N O Ca O O O P O O O Ca P O O

6. Notes #2: Balancing Equations
WNHS Chemistry

7. BALANCING EQUATIONS ____H2 + ____O2 → ____H2O PROBLEM!
Equation isn’t balanced!
BALANCING EQUATIONS
REACTANTS
PRODUCTS
____H ____O → ____H2O
Rules for Balancing Equations:
Law of Conservation of Mass says start = finish
You NEVER change the chemical formula!
AKA → NEVER add subscripts (ex: H2O vs. H2O2)
Can only add coefficients! They will affect entire compound.
If no coefficient, assume “1”

8. BALANCING EQUATIONS ____H2 + ____O2 → ____H2O 2 H 2 O 2 1
1st: Atom Inventor y 2 H 2 O H H O O H H O H H 2 1
2nd: Visual Use this to help you O H H
4th: # molecules = coefficient
3rd: Re-Inventory after each added molecule until both sides are the same

9. ____Na + ____O2 → ____Na2O
BALANCING EQUATIONS
____Na ____O → ____Na2O
1st: Atom Inventor y 1 Na 2 Na O Na Na O O Na 2 O 1
2nd: Visual Use this to help you Na Na Na O Na
4th: # molecules = coefficient
3rd: Re-Inventory after each added molecule until both sides are the same

10. ____Fe + ____O2 → ____Fe2O3
BALANCING EQUATIONS
____Fe ____O → ____Fe2O3
1st: Atom Inventor y 1 Fe 2 Fe Fe O O O O O Fe O Fe O O 2 3
2nd: Visual Use this to help you Fe Fe O O O O O Fe Fe
4th: # molecules = coefficient
3rd: Re-Inventory after each added molecule until both sides are the same