1. Stoichiometry

2. Stoichiometry Calculating quantities in a chemical reaction Tricycle:
A tricycle is composed of 1 frame and 3 wheels.
If you have 1 doz frames, how many tricycles can you make?
1 doz or 12 tricycles
If you have 1 doz wheels, how many tricycles can you make?
4 tricycles or 1/3 doz

3. If you have 1 mol of frames, how many tricycles can you make?
1 mol of tricycles
If you have 100lbs of frames can you make 100 lbs of tricycles?
NO!
Not the same because they don’t weigh the same

4. 2 moles of silver nitrate yields 1 mole of silver sulfide.
2 AgNO3 + H2S  Ag2S HNO3
2 moles of silver nitrate yields 1 mole of silver sulfide.
1 mole hydrogen sulfide yields 1 mole of silver sulfide.
Conversion factors:
2 moles AgNO3 = 1 mol Ag2S
1 mol H2S = 1 mole Ag2S

5. 1.75 mol Ag2S 2 AgNO3 + H2S  Ag2S + 2 HNO3
Q: How many moles of Ag2S will be produced from 3.5 moles of AgNO3?
What happens if grams is involved?
Use Molar Mass!
1.75 mol Ag2S

6. Q: How many grams of Ag2S will be produced from 3. 5 moles of AgNO3
Q: How many grams of Ag2S will be produced from 3.5 moles of AgNO3? A balanced chemical equation tells the mole:mole ratio between different compounds in the equation.

7. Tell-tale sign of Stoichiometry
If you are given information about one substance and asked about a different substance, it is a stoichiometry problem.

8. Practice
What is the mass of Mg(OH)2 that will react with 1.20g of HCl?
Mg(OH) HCl  MgCl H2O 2 2
0.956g Mg(OH)2