1. Limiting Reagents

2. Materials You Need
Note Sheet
Periodic Table
Calculator

3. Limiting Reagent
The reagent that determines the amount of product that can be formed by a reaction.
The reaction occurs only until the limiting reagent is used up.

4. The reactant that is not completely used up in the reaction.
Excess Reagents
The reactant that is not completely used up in the reaction.

5. Let’s make a smore! 1 marshmallow 2 graham crackers ½ chocolate bar
Recipe:
We have:
1 marshmallow
2 graham crackers
½ chocolate bar
3 marshmallows
4 graham crackers
2 chocolate bars
How many Smores can we make??

6. How do we know it is a L.R. Problem?
Two quantities of reactants are given

7. Practice Problem 1
If 4.0 moles of hydrogen gas and 1.0 mole of oxygen gas are reacted, how many grams of water will be produced?

8. Practice Problem 1 4.0 moles H2
If 4.0 moles of hydrogen gas and 1.0 mole of oxygen gas are reacted, how many grams of water will be produced?
4.0 moles H2

9. Practice Problem 1 4.0 moles H2 2 moles H2O 2 moles H2
If 4.0 moles of hydrogen gas and 1.0 mole of oxygen gas are reacted, how many grams of water will be produced?
4.0 moles H2
2 moles H2O
2 moles H2

10. Practice Problem 1 4.0 moles H2 2 moles H2O 2 moles H2 =4.0 moles H2O
If 4.0 moles of hydrogen gas and 1.0 mole of oxygen gas are reacted, how many grams of water will be produced?
4.0 moles H2
2 moles H2O
2 moles H2
=4.0 moles H2O

11. Practice Problem 1 4.0 moles H2 2 moles H2O 2 moles H2 =4.0 moles H2O
If 4.0 moles of hydrogen gas and 1.0 mole of oxygen gas are reacted, how many grams of water will be produced?
4.0 moles H2
2 moles H2O
2 moles H2
=4.0 moles H2O
1.0 moles O2

12. Practice Problem 1 1 mol O2 4.0 moles H2 2 moles H2O 2 moles H2
If 4.0 moles of hydrogen gas and 1.0 mole of oxygen gas are reacted, how many grams of water will be produced?
4.0 moles H2
2 moles H2O
2 moles H2
= 4.0 moles H2O
1.0 moles O2
2 moles H2O
1 mol O2

13. Practice Problem 1 1 mol O2 4.0 moles H2 2 moles H2O 2 moles H2
If 4.0 moles of hydrogen gas and 1.0 mole of oxygen gas are reacted, how many grams of water will be produced?
4.0 moles H2
2 moles H2O
2 moles H2
= 4.0 moles H2O
1.0 moles O2
2 moles H2O
1 mol O2
= 2.0 moles H2O

14. Practice Problem 1 2.0 moles H2O
If 4.0 moles of hydrogen gas and 1.0 mole of oxygen gas are reacted, how many grams of water will be produced?
2.0 moles H2O

15. Practice Problem 1 2.0 moles H2O 18.0 g H2O 1 mol H2O
If 4.0 moles of hydrogen gas and 1.0 mole of oxygen gas are reacted, how many grams of water will be produced?
2.0 moles H2O
18.0 g H2O
1 mol H2O

16. Practice Problem 1 = 36 g H2O 2.0 moles H2O 18.0 g H2O 1 mol H2O
If 4.0 moles of hydrogen gas and 1.0 mole of oxygen gas are reacted, how many grams of water will be produced?
2.0 moles H2O
18.0 g H2O
1 mol H2O
= 36 g H2O

17. Practice Problem 2
When 87.0 grams of aluminum reacts with 402 grams of hydrobromic acid, how many liters of hydrogen gas are formed?

18. = 4.83 mol H2 = 2.48 mol H2 = 55.6 L H2 87.0 g Al 1 mol Al 3 mol H2
402 g HBr
1 mol HBr
3 mol H2
80.9 g HBr
6 mol HBr
= 2.48 mol H2
2.48 mol H2
22.4 L H2
1 mol H2
= 55.6 L H2

19. Questions? Concerns?