Chapter 11 The
Mole
Section 11.1
Please have a highlighter and your periodic table out
• 3b-Students know the quantity one mole is set by
defining one mole of carbon 12 atoms to have a mass
exactly of 12 grams.
• 3c- Students know one mole equals 6.02 x1023 particles
(atoms or molecules)
Standard 3
•
•
•
•
•
•
Unit Numerical Value
Dozen
12
Pair
2
Ream
500
Gross
144
Mole
6.02 x 1023
Example
Eggs in a carton
Shoes
Sheets of paper
Pencils in a box
Particles
Words used for counting:
• 1 dozen is always equal to 12
• 1 mole is always equal to 6.02 ×1023
Never Changes
•6.02 ×1023 is also called Avogadro’s number
•It was named after this guy:
Amedeo Avogadro of Italy
Avogardro’s number
• The mole is the SI unit used for
counting the amount of a substance
• 1 mole = 6.02 ×1023 particles
Particles can be atoms, ions, molecules,
formula units, etc.
Other names for a
particle
• 0.5 moles = 3.01 ×10 23
• 1 mole = 6.02 ×10 23
• 2 moles = 1.20 ×10 24
• 3 moles = 1.80 ×10 24
• 4 moles = 2.41 ×10 24
Multiplying a mole
• 602, 000, 000,000,000,000,000,000
particles
• 602 SEXTILLION!!!!
How big is a mole
• The average atomic mass (on the periodic
table) tells you how much one mole of an
element weighs (it is also called the molar
mass).
• –Ex. one mole of oxygen atoms weighs
16.00 grams
• –Ex. one mole of potassium atoms weighs
39.10 grams
1 mole=atomic mass of
each element
• Carbon-12 has exactly 6 protons and 6
neutrons
• So it has an atomic mass of exactly 12.00
Scientists measured out exactly 12 grams of
carbon-12
• The sample had 6.02 ×1023atoms of carbon
• They set 6.02 ×1023to be one mole (like 12 is
one dozen)
How did scientist come
up with this number?
•
•
•
•
•
1. Start with what is given.
2. (given) x -----------3. The units that are given are placed in the denominator
4. Your unknown is placed in the numerator
5. Multiply the top and divide by the bottom
Steps for mole
caluculations
• How many minutes are in 120 seconds?
Example of time
1. Determine the number of atoms in 3.00
moles(mol) of Zn?
2. Given 4.00 mole (mol) of AgNO3
determine the number of formula
units(FMU).
Pg 311 examples
• 3. Calculate the number of molecules in
11.5 mol of H2O.
• 4a) 5.75 x 1024 atoms Al how many
moles?
Pg 311 examples
continued…
• 4b) 3.75 x1024 molecules CO2 How many
moles?
• 4c) 3.58 x 1023 Formula units ZnCl2 How
many moles?
• 4d) 2.50 x1020 atoms Fe. How many
moles?
On your own in your notes
needs to be stamped for
points
Molar Mass and
Mole to gram
calculation
Standard 3.d- Students know how to determine the
molar mass of a molecule from its chemical formula
and a table of atomic masses.
• The molar mass of a compound
can be calculated solving for
the sum of the products of each
elements’ mass times the
number of atoms present.
Molar Mass
17
• EX: Find the molar mass of the following
compounds:
- P2O5
- C6H12O6
- Fe2(SO4)3
Examples
18
• EX: Find the molar mass of the
following compounds:
- N2O3
- KC2H3O2
- Ca3(PO4)2
On your own
19
• EX: Perform the following
conversions:
- Convert 5.0 moles of Na to grams
- Convert 12.0 moles of He to grams
- Convert 213 grams of NF3 to moles
Moles to Grams
20
• PP: Perform the following
conversions:
- Convert 6.50 moles of O to grams
- Convert 25.0 moles of Fe to grams
- Convert 0.40 moles of Ne to
grams
On your own
21