1. The Mol

2. The Atomic Mass Unit (amu)1
The atomic mass Standard
112 2
the mass of an atom of carbon-12
Recently, the designation amu has been changed to the Dalton (D)
mass of 28Si atom  mass of 12C atom =
Observed:
Isotopic mass 28Si = measured mass ratio x mass of 12C
Thus:
= x amu =

3. The Mole The amount of a substance that contains the
same number of fundamental units as there
are atoms in exactly 12 g of carbon-12 ( 12C).

4. The Mole (mol) (1) 6.022 x 10 23 fundamental units of matter
Type of matter
Fundamental Unit
Elemental (monatomic; e.g. He, Fe, Xe)
Atom
Elemental (molecular; e.g. O2, H2, P4)
Molecule
Compounds , covalent ( e.g. H2O, ICl3)
Molecule
Formula Unit
Compounds, ionic (e.g. NaCl, Al2O3 )
6.022 x atoms He
  mol He
6.022 x formula
units
 
mol Al2O3
1 mol He:
1 mol Al2O3:
6.022 x molecules H2O
  mol H2O
1 mol H2O:

5. The Mole (mol) Elemental Matter
That quantity of matter possessing a mass equivalent to the atomic weight of an element expressed in grams.
(2).
(monoatomic elements) 80 Hg
200.59 10 Ne
20.179 Ne
Atomic Wt.
( avg. mass of Ne atoms): amu Hg
Atomic Wt.: amu
Mass of 1 mol Hg atoms: g
Mass of 1 mol Ne atoms: g
-or-
g Hg
mol Hg
-or- -
g Ne
mol Ne

6. How many atoms are found in 0.211 g of Cu?
g Cu  mol Cu  atoms Cu
atoms Cu x  mol Cu
mol Cu
x 
g Cu
g Cu
= atoms Cu
6.022 x 1023 atoms Cu x  mol Cu
mol Cu
x 
g Cu
0.211 g Cu
= x 1021 atoms Cu

7. What is the mass of 1 atom of Ag?
atom Ag  mol Ag atoms  g Ag
g Ag x  mol Ag
mol Ag
x 
atom Ag
atom Ag
= g Ag
107.9 g Ag x  mol Ag
mol Ag
x 
6.022 x atoms Ag
1 atom Ag
= x g Ag

8. How many grams is 0.004986 mols Hg?
mol Hg  g Hg
g Hg
mol Hg x    = g Hg
mol Hg
g Hg
mol Hg x       = g Hg
mol Hg

9. Which is the larger number: The number of human beings on earth
( approx billion or x 109)
The number of Cu atoms in a single copper crystal
( g Cu) .

10. The Mole (mol) Compounds
That quantity of matter possessing a mass equivalent to the formula weight expressed in grams.
(2).
(compounds)
Al2O3
H2O2
Al2O3
Formula Wt:
( avg. mass of one formula unit): 102 amu
H2O2
Formula Wt :
(avg mass of a molecule): amu
Mass of 1 mol Al 2O3 :
102. g
Mass of 1 mol H2O molecules: g
-or-
102. g Al 2O3
mol Al 2O3
-or- -
g H2O2
mol H2O2

11. Molar Relationships O H H O H2O2
6.022 x 1023 atoms Ca x 1023 molecules H2O2
mol Ca mol H2O2
40.08 g Ca g H2O2
mol Ca mol H2O2 20 Ca
40.08

12. Molecular Formula
Shows the exact number of atoms of each type in a molecule
3 S4Cl2
Coefficient: Indicates the number of molecular units
Subscripts: Indicate the number of atoms of each kind in the molecular unit

13. Molecular Formula
Shows the number of mols of atoms of each type in one mol of molecules
3 S4Cl2
Coefficient: Indicates the number of mols of molecular units
Subscripts: Indicate the number mols of atoms of each kind in one mole of molecules
4 mols S 
mol S4Cl2
2 mols Cl
mol S4Cl2
3 mols S4Cl2 of molecules

14. Shows the number of mols of atoms of each type in one mol of molecules
Molecular Formula
Shows the number of mols of atoms of each type in one mol of molecules
3 S4Cl2
Coefficient: Subcripts:
Indicates the Indicate the number mols
number of mols of atoms of each kind in
molecular units one mole of molecules
4 mols S mols Cl
3 mols S4Cl mol S4Cl2 mol S4Cl2

15. Stoichiometry
Quantitative relationships expressed in the formula of a compound or molecular element.

16. Stoichiometry in Compounds
Al2(SO4)3 7 H2O Mo(CO) CH3(CH2)7 OH
2 Al atoms CO molecules C atoms
1 Al2(SO4)3 7 H2O Mo(CO)6 molecule CH3(CH2)7 OH
(formula unit) molecule
7 H2O molecules Mo atom H atoms
7 H2O molecules
1 Al2(SO4)3 formula unit

17. Stoichiometry in Compounds (mols)
Al2(SO4) H2O
2 Al atoms mols Al atoms
1 Al2(SO4)3 7 H2O unit mol Al2(SO4)3 7 H2O formula units
7 H2O molecules mols H2O mol ecules
1 Al2(SO4)3 7 H2O unit mol Al2(SO4)3 7 H2O formula units
7 H2O molecules mols H2O molecules
1 Al2(SO4)3 unit mol Al2(SO4)3 unitss

18. How many grams S are found in 4.979g S4Cl2 ?

19. g S4Cl2 mol S4Cl2 mol S g S mol S4Cl2 mol S g S
g S4Cl2 x x x
g S4Cl mol S4Cl2 mol S
mol S4Cl mol S g S
4.979 g S4Cl2 x x x =
199.1g S4Cl mol S4Cl mol S
= g S

20. How many grams CO will be obtained when 0.5412 g Mo(CO) 6 decomposes?
Mo(CO) 6 (s) Mo(s) + 6CO(g)

21. g Mo(CO) 6 mol Mo(CO) 6 mol CO g CO mol Mo(CO) 6 mol CO g CO
g Mo(CO) 6 x x x
g Mo(CO) mol Mo(CO) mol CO
mol Mo(CO) mol CO g CO
g Mo(CO) 6 x x x
264.00g Mo(CO) mol Mo(CO) mol CO
= g CO

22. How many grams H2O will be obtained when 5. 950 g Al2(SO4)3
How many grams H2O will be obtained when g Al2(SO4) H2 O are heated?
Al2(SO4) H2 O (s) Al2(SO4)3 (s) + 7 H2 O(g)

23. g Al2(SO4)3 . 7 H2 O mols Al2(SO4)3 . 7 H2 O mols H2 O g H2 O
mol Al2(SO4) H2 O mols H2 O
g Al2(SO4) H2 O x x x . . .
g Al2(SO4) H2 O mol Al2(SO4) H2 O
g H2 O
x = g H2 O
mol H2 O
1 mol Al2(SO4) H2 O 7 mols H2 O
5.950 g Al2(SO4) H2 O x x x
318.1 g Al2(SO4) H2 O 1 mol Al2(SO4) H2 O
18.01 g H2 O
x = g H2 O
1 mol H2 O

24. How many grams of hydrogen atoms are contained in 50.0 g H2O?
How many grams C atoms are provided by grams of propane ( C3 H8)?

25. 1 mol H2O 2 mols H 1.008 g H 1 mol C3 H8 3 mol C
How many grams of hydrogen atoms are contained in 50.0 g H2O?
1 mol H2O mols H g H
50.0 H2O x x x = g H
18.0 g H2O 1 mol H2O mol H
How many grams C atoms are provided by grams of propane ( C3 H8)?
1 mol C3 H mol C
12.22 g C3 H8 x x x ...
44.0 g C3 H mol C3 H8
g C
x = 1.00 g C
mol C

26. How many grams of potassium will be found in 0
How many grams of potassium will be found in g of potassium bicarbonate?