1. DO NOW-on the back of your notes
1) How many moles of Sulfur is needed to react with .78 mol of Iron
2 Fe S  Fe2S3
Reaction on

2. After today you will be able to…
Calculate the number of grams produced or reacted of a substance given a chemical equation

3. There are two steps needed for these calculations:
Convert moles of knownmoles of unknown using the mole ratio (We learned this yesterday!)
Convert moles of unknown grams (Using MM of the unknown.)

4. Mass-Mass Calculations
Example: What mass of silver chloride will react with .55 mol of aluminum?
__Al 1
__ AgCl 3
__ Ag 3 +
__ AlCl3 1  + 1 Al Ag Cl 1 3
Review!
1Ag = )
K: .55 mol Al 3 3
1Cl =35.45(1)
U: ? gAgCl 3
143.32g
.55 mol Al 1
3 mol AgCl
1 mol Al
gAgCl
1 mol AgCl x x
239g AgCl =

5. Mass-Mass Calculations
Example: What mass of oxygen gas would be produced from the decomposition of .411 mol of lithium chlorate? 2
__Li(ClO3)
__ LiCl 2 +
__ O2 3 
1Li =6.94(1)
K: .411 mol Li(ClO3)
1Cl =35.45(1)
3O =16.00(3)
U: ? gO2
90.39g
.411 mol Li(ClO3) 1
3 mol O2
2 mol Li(ClO3)
32.00 gO2
1 mol O2 x x
19.8 gO2 =

6. SUMMARY OF IMPORTANT POINTS:
Molar mass (MM) is ALWAYS equal to ONE mole!
The ONLY time the number of moles is different than ONE (1) is when you are doing the MOLE RATIO STEP!

7. Questions? Practice Time!!
Reaction on