1. The Mole

2. Learning Objective I CAN define and use the concept of a mole.
I CAN use the mole concept to calculate the number of atoms, ions, or molecules in a sample of material.

3. Criteria for Success
I CAN define the mole in terms of Avogadro’s number.
I CAN define molar mass.
I CAN solve problems involving the conversion of mass in grams, amount in moles, and number of atoms in an element.

4. Avogadro’s Number = 1 mole = ___________________ (or _______________)
The Mole
The mole: (abbreviated ______) is the SI unit for amount of a substance.
The number of particles in exactly one mole of a substance is known as Avogadro’s Number.
Avogadro’s Number = 1 mole = ___________________ (or _______________)
mol
6.022 x 1023
6.022E23

5. The Mole mass g/mol atomic mass
Molar mass: The ______ of one mole of a pure substance, written in units of _______.
The molar mass of an element is numerically equal to the __________________ of the element in atomic mass units
mass
g/mol
atomic mass

6. The Mole
Use caution with diatomic elements (Br2, I2, N2, Cl2, H2, O2, F2)
Exist in PAIRS of atoms
Molar mass is DOUBLE what you would expect
Molar mass of hydrogen gas (H2) isn’t g/mol, it’s _______ g/mol.
2.016

7. The Mole 26.98 g/mol 6.022 x 1023 12.01 g/mol 6.022 x 1023 4.00 g/mol
Element
Molar Mass
# of Moles
# of atoms
Representative Size
Aluminum (Al)
1 mole Al
Carbon (C)
1 mole C
Helium (He)
1 mole He
Oxygen Gas (O2)
1 mole O2
26.98 g/mol
6.022 x 1023
12.01 g/mol
6.022 x 1023
4.00 g/mol
6.022 x 1023
32.00 g/mol
1.204 x 1024
2 moles of oxygen atoms

8. The Mole units fractions It’s about counting!
Chemists use molar mass and Avogadro’s number as a conversion factor in chemical equations
Conversion factor = ________ = dimensional analysis = ____________
Yes, you have to show your work…
units
fractions