1. How to find the limiting reactant
Stoichiometry
How to find the limiting reactant

2. Stoichiometry
Involves measuring/calculating the amounts of elements/compounds involved in a chemical reaction
Ex: Find grams of chlorine needed to produce 737g of sodium chloride.

3. Na + Cl2  NaCl

4. LR always determines how much product will be made!!!!
Limiting Reactant
Limiting reactant/reagent (used up/runs out of first)
Excess reactant/reagent (left over after reaction done)
Usually in chemical reactions one reactant is used up before the other and the reaction stops.
Rarely are reactions in perfect ratios!!
2Mg + O2  2MgO
LR always determines how much product will be made!!!!
Excess reactant, it is left over
The limiting reactant (LR), it is used up first
4 moles
4 moles
Run the reaction once, how much Mg and O2 is left?
Run the reaction again, how much Mg and O2 is left?
Can you run the reaction again?
Why not?

5. + + + + = = = = Buns Hot dogs product Wheels Frames Bikes LR 10 8 8 512 LR

6. Ex: If 79.1g of Zinc reacts with 96.7g of HCl to produce ZnCl2 and H2.
Find the limiting reactant
How much ZnCl2 is produced?
How much grams of excess reactant?

7. Zn + HCl  ZnCl H2