Moles can be converted to grams, particles, and other units using dimensional analysis. To convert between moles and grams, divide the mass by the molar mass. To convert between moles and particles, multiply or divide by Avogadro's number. Dimensional analysis keeps track of units and is important for stoichiometry calculations. Practice problems provide examples of converting between moles, grams, and particles for different compounds.

1. MOLE
CONVERSIONSUnit 7: The Mole

2. WHY DO WE NEED TO CONVERT
MOLES?
• Moles can be converted to find the
number of grams or the number of
particles in a sample.
• If you have moles, grams, or particles you
can convert it to another unit.
• Particles can be atoms (single element),
molecules (covalent compound), or
formula units (ionic compound)

4. WHAT ARE THE CONVERSIONS?
• Mass  Moles
– divide by molar mass
• Particles  Moles
– multiply by Avogadro’s number
• Particles  Mass
– divide by Avogadro’s number; multiply by
molar mass

5. WHAT IS DIMENSIONALANALYSIS?
• Dimensional analysis is a way of
organizing calculations to keep track of
units.
• You must show your work this way – if you
get used to it now, stoichiometry (next
unit) will be easier!

6. PRACTICE
• How many moles are in 45.98 g of Na?

7. PRACTICE
• How many particles are in 2 moles of
NaCl?

8. PRACTICE
• How many grams are in 6.02x1023
molecules of water?

9. PRACTICE
• How many moles are in 8.91x1024 atoms
of magnesium?