1. Atomic Mass is the Mass of One Mole of an Element
One mole of chlorine is Avogadro’s number of chlorine atoms:
602,000,000,000,000,000,000,000 chlorine atoms,
or better yet, 6.02 x 1023 chlorine atoms
One mole of chlorine has a mass of grams 20 30 10 40 50

2. Molecular Mass is the Mass of One Mole of a Molecular Compound
One mole of carbon tetrachloride is Avogadro’s number of CCl4 molecules
12.01 g/mol: Atomic mass of carbon
35.45 g/mol: Atomic mass of chlorine
1 x =
+ 4 x =
Molecular mass of CCl4: g/mol
CCl4

3. Formula Mass is the Mass of One Mole of the Chemical Formula of a Compound
One mole of sodium chloride is Avogadro’s number of NaCl formula units. Salt is a crystal. NaCl does not form a molecule made of one Na and one Cl.
22.99 g/mol: Atomic mass of Na
g/mol: Atomic mass of Cl
58.44 g/mol: Formula mass of NaCl
NaCl crystal

4. Molar Mass is the Mass of One Mole of:Cl
An element
A molecular compound
An ionic compound formula
CCl4
NaCl

5. Conversions Transfer Through the Mole
Volume of gas
at STP in liters
Use 22.4
Mass in grams
Use Molar Mass in L
mole
grams
mole
moles
Particles (Atoms, Molecules or Formula Units)
Use Avogadro’s Number: 6.02 x 1023
particles
mole