3. Mass Amount of substance
50 g of
2 kg of flower
mangosteen
3 kg of
papaya
4. Molar mass
Mass of one mole of element or
compound in gram
Unit
Gram per mol (g/mol)
5. MOLAR MASS OF AN ELEMENT
is found by looking at the atomic mass of
the element on the periodic table
Molar mass = (RAM) Relative Atomic Mass
= (RMM) Relative Molecular
Mass
6. Cobalt = 59g Bromine = 80g
1 mole
element
Iron = 56 g Calcium = 40 g
7. MOLAR MASS OF A CHEMICAL
COMPOUND
Molar masses of chemical compounds are
equal to the sums of the molar masses of all
the atoms in one molecule of that compound
example : NaCl
molar mass = molar mass of one atom of sodium
+
molar mass of one atom of chlorine
Answer : 58.5 g
8. EXAMPLE OF CHEMICAL COMPOUND
Sodium Chloride, NaCl
23g of sodium + 35g of chloride
=58 g
Water, H2O
2g hydrogen + 16g oxygen
= 18g
9. MOLAR MASS RELATION
TO AVOGADRO CONSTANT
Molar mass = 1 mol mass
1 mol = 6.02 X 1023
Molar mass = mass of 6.02 X 1023
10. EXAMPLE
1 mole Aluminum
Relative
atomic mass
1 mol Aluminum has a mass of 27 g
1 mol of Aluminum contain 6.02 X 1023 atoms
6.02 X 1023 Atom of Aluminum has mass of 27g
11. sulfur water
1 mole - 32 g 1 mole - 18 g
copper
1 mole - 64 g
All this substance contain 6.02 X 1023
12. Building of a house
One mole of nails contains 6.022 x 1023 nails
One mole of screws contains 6.022 x 1023 screws
One mole of woods contains 6.022 x 1023 woods
13. 1 Mol = 6.02 X 10 23
SUBSTANCE He NaCl
H 2O
mol 1 2 3
Mass
(g) 4.0 x 1 18.0 x 2 58.5 x 3
6.02 X 1023 6.02 X 1023 6.02 X 1023
NA x 1 x 2 x 3
