3. How about such as tablespoon of sugar
or a tablespoon of salt?
How will you determine the number of
particles in a tablespoon of salt?
Is the number of particles in a
tablespoon of sugar the same as the
number of particles in a tablespoon of
salt?

4. Lorenzo Romano Amedeo
Carlo Avogadro di Quaregna
e di Cerreto,
Count of Quaregna and Cerreto
was an Italian scientist.
He is most noted for his
contributions to molecular
theory, including what is
known as Avogadro's law.

5. In tribute to him,
the number of
elementary entities
(atoms, molecules, i
ons or other
particles) in
1 mole of a
substance,
6.02214179(30)×1023
is known as

6. Question:

7. One mole of cotton has the same number
of particles as one mole of salt.
One mole of an element contains the
same number of atoms as a mole of any
other element.
1 M of a given element = 1 M of other
elements
1 mole of a compound = 1 mole of other
compounds

9. 1 mole = 6.02 ×1023
Multiply 2 by
Avogadro’s number.

10. 1. Atomic mass of C?
2. Atomic masses of
H and O?
3. Atomic masses of
Na and Cl?

11. One mole of any substance
contains the same number of
particles.
What about the mass of a
mole of a substance?
Is it same for all substances?

12. The mass of an element or
compound depends on the mass of
its particles.
Therefore, one mole of hydrogen
has a mass dependent on it atomic
mass. - MOLAR MASS
MOLAR MASS- the mass in grams
that is numerically equal to the
atomic mass. The unit of molar
mass is grams / mole (g/mol).

13. Answer: 12.01 amu
What is the molar mass of
carbon?
The molar mass of carbon is 12.01 g.
How many atoms are I 12.01g of
carbon?
6.022 x 10^23 atoms

14. The atomic mass of oxygen is
_______. Its molar mass is
_____________. There are ______
atoms found in ________ g of
oxygen.
The atomic mass of sodium is
_________. Each mole of sodium has
a mass of ______. Every ______ g of
sodium has _______ atoms.

15. Number of moles Cl = given mass
molar mas
= 70.9 g
35.45 g/mol
= 2 mol
Number of moles = given mass
molar mass

16. 1. How many moles are there in
6.05 g of carbon?
2. How many moles are there in
46.00 g of sodium?

17. 1. Find the molar mass of water.
a. Multiply the atomic mass of H by 2 and
that of O by 1.
H = 2 x 1.008 = 2.016
O = 1 x 16.00 = 16.00
18.016 or 18.02
Number of moles (H2O) = 36.04 g
18.02 g/mol
= 2.0 mol

18. Let’s See What You Have Learned
Α. Determine the molar masses of the
following:
1. acetic acid (CH3COOH)
2. agua oxigenada (H2O2)
3. ammonia (NH3)
Β. Determine the number of moles in
1. 120.0 g of acetic acid
2. 17.0 g of agua oxigenada
3. 51.0 g of ammonia

19. Let’s Remember!
♦ The mole is a unit for counting
particles in a given mass of a
substance. Each mole of a substance
is made up of 6.022 × 1023 particles.
♦ The molar mass of a substance is the
mass in grams that is numerically
equal to the atomic mass or formula
mass of the substance.