1. Mole Calculations

2. Mole Calculations Symbol Quantity Unit n Moles (amount) mol m Mass g M
Molar mass
g/mol N
Number of…
Atoms, molecules, ions NA
Avogadro’s constant
6.02 X 1023

3. Mole Calculations Factor Label! Let the units guide you MM = m/n m
n = m/M
m = Mn m
N = nNA
n = N/NA n MM
Factor Label!
Let the units guide you

4. Determining Molar Mass
Recall: Add the individual molar masses
MM(NH4)3PO4 = 3(N + 4H) + P + 4O
= 3N + 12H + P + 4O
= 3(14.01) + 12(1.01) (16.00)
= g/mol

5. Converting Mass to Moles
MM = m/n
n = m/M
m = Mn
Converting Mass to Moles
Example: How many moles of calcium carbonate are there in 1.5 kg?
n = m/MM
= 1500 g  g/mol
= 15 mol
Given:
m CaCO3 = 1500 g
MM = (3 X 16.00)
= g/mol
n = 1500 g X 1 mol g
= 15 mol

6. Converting Moles to Mass
MM = m/n
n = m/M
m = Mn
Converting Moles to Mass
Example: What is the mass in grams of mol of sodium sulfate?
m = MMn
= g X mol
1 mol
= 49.1 g
Given:
n Na2SO4 = mol
MM = (2 X 22.99) (4 X 16.00)
= g/mol

7. Finding Number of Atoms or Molecules
N = nNA
Finding Number of Atoms or Molecules
How many atoms of copper are there in 2.0 moles?
N = nNA
= 2.0 mol X 6.02 X 1023 atoms
1 mol
= 1.2 X1024 atoms of copper
Given:
n Cu = 2.0 mol
NA = 6.02 X 1023

8. How many sugar (sucrose, C12H22O11) molecules are there in a 1
How many sugar (sucrose, C12H22O11) molecules are there in a 1.00 kg bag?
Given:
m = 1.00 X 103 g
MM = (12 X 12.01) + (22 X 1.01) + (11 X 16.00)
= g/mol
n = 1.00 X 103 g X 1 mol g
= mol
N = nNA
= mol X 6.02 X 1023 molecules
1 mol
= 1.76 X1024 molecules of sugar

9. How many carbon atoms are there in a 1
How many carbon atoms are there in a 1.00 kg bag of sugar (sucrose, C12H22O11) ?
N = 1.76 X 1024 molecules of sugar X 12 carbon atoms
1 molecule sugar
= X 1025 carbon atoms

10.     Mass (g) Concentration (mol/L) Moles (mol)
Vol
g/mol  
Moles
(mol) 
6.02 X 1023
22.4 
# of molecules/atoms/ions
Volume (L) at STP
(0˚C, kpa)

11. Homework Finish Mole Worksheet P. 170 #7-13 P. 171 #1-5 P. 172-173#1-8
Change “volume” to “mass” in Q3
P. 170 #7-13
P. 171 #1-5
P #1-8