Moles Notes (Ch. 7)
A. Counting _____________
1. Suppose you want to know the mass of _____________. How would you
measure it?
2. If you have a bag of ________, how would you figure out how many
_______ are in the bag?
B. Counting Atoms
An atom is ______ that we can’t weigh it on our regular scale. How can we
measure or count the # of atoms we add?
C. What is a Mole?
1 mole = ____________
Atomic Mass of Each Element = Mass of ______ mole
= Mass of ___________atoms
_______________________________
_____________’s number
1 mol = ________________ items
602000000000000000000000
A ______ _____ amount!!!!
D. Avogadro’s number
So, why do we use Avogadro’s #?
Mass of 1 proton = ________________g
Mass of 1 neutron = _______________g
__________ X ____________= 1 = close to a
(or Mass of n)
whole #
Easy to work with.
E. Formula Mass
______________________
-Look up the mass of each element from the PT and multiply by ___________
and _______ them all up.
Ex. (NH4)3PO4
Ms. Park
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F. Molar Mass
Mass of ________ of an element or compound. (usu. _______ mass is same as
___________ mass.)
Units of molar mass ______________________________
_______________________________
____________________________
G. Molar Mass Example:
1. Single element
a. carbon
b. aluminum
c. zinc
2. Compound
a. Water
b. Sodium Chloride (salt)
Learning Check
Find the formula mass (or molar mass).
1. KMnO4
2. Ca(NO3)2
3. Fe2(SO3)3
4. Mg3(PO4)2
5. CuSO4 * 5 H2O
6. Zn3(PO4)2 * 4 H2O
H. Molar Volume
STP for gases
= Standard Temperature (______ or _______)
= Standard Pressure (_________)
At STP, ________of gas occupies ______ L of volume regardless of the
_______ of the gas.
volume of 1 mole of any gas = ____ L @ STP
I. Molar Conversions
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J. _______________ Method (_______________________________________)
1 mole = 6.02 x 1023 atoms/molecules/
particles
1 mole = molar mass (g)
1 mole = 22.4 L
K. Match the units diagonally.
Divide
Multiply
L. One Step Conversions
Mole <-> Mass
Mole <-> Atoms/Molecules
Mole <-> Volume of gas at STP
M. Two Step Conversions
Mass
-> Mole
Volume
-> Mole
Atoms/Molecules -> Moles
-> Volume or Atoms/Molecules
-> Mass or Atoms/Molecules
-> Mass or volume
N. Molar Conversion Examples
1. How many moles of carbon are in 26 g of carbon?
2. How many molecules are in 2.50 moles of C12H22O11?
Ms. Park
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3. Find the mass of 2.1 x 1024 molecules of NaHCO3.
Learning Check
1. What is the mass of 3 moles of CuSO4?
2. How many molecules are in 3 moles of CuSO4?
3. At STP, what is the volume of 4 moles of O2?
4. How many moles are in 10 g of carbon?
5. How many moles are in 75 L of chlorine gas at STP?
6. How many moles are in 2.75 x 1024 molecules?
Ms. Park
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