Transcript The Mole and Avogadro`s Number

The Mole
and Avogadro’s Number
• Mole (n): the amount of substance
• 6.02x1023 particles (atoms or
molecules) of a substance
• The same number of particles as
atoms in 12 grams of carbon-12
23
6
.02
x
10
particles
1
mole
23
.02
x
10
particle
1
mole 6
Review
• How many atoms are there in 1.2
moles of oxygen?
• Calculate the number of moles of
nitrogen equal to 3.45x1015 atoms of
nitrogen.
Counting Atoms
•
•
•
•
•
CO
CO2
Fe(NO3)3
C6H12O6
potassium carbonate
• How many molecules in 5 moles of
water?
• How many hydrogen atoms in 5
moles of water?
• How many atoms in 5 moles of
water?
1. How many chloride ions are there in
zinc chloride?
2. A sample of zinc chloride contains
3.1x1019 molecules.
a. How many moles is this?
b. How many zinc ions?
c. How many chloride ions?
• Stop.
Masses of Compounds
• Atomic mass (A): the mass of an
atom of an element relative to
(compared to) other elements (g/mol)
• Ionic: formula unit
• Molecular (covalent): molecule
• Formula mass: sum of the atomic
masses of the atoms in the
compound’s formula (IONIC) (g/mol)
• Molecular mass: sum of the atomic
masses of all the atoms in one
molecule (COVALENT) (g/mol)
• Molar mass (M): the mass of one
mole of any substance (g/mol)
– atoms, molecules, ions, etc.
Ionic
Formula
Mass
Molar
Mass
Covalent
Molecular
Mass
Calculating Molar Mass
• Stop.
1. Calculate the mass of 1.98 moles of
iron (II) nitrate.
2. How many molecules are there in
1.00 grams of iron (II) nitrate?
3. Calculate the mass of one molecule
of iron (II) nitrate.