1. Using Conversions

2. Avogadro’s Number The SI unit for amount is called the mole (mol).
1 mole = 6.02 x 1023 particles
Particles can be: ●atoms (Na, Fe, Cu)
●ions (Na+, Fe3+, Cu2+)
●molecules (covalent, diatomic)
●formula units (ionic)

3. Converting molar mass/moles
1 mole X
# grams X
# grams X
1 mole X
X = symbol/formula # = molar mass

4. 1) Given 2) Use molar mass 1 mol Cu = 63.55 g Cu 75.92 g Cu x
Example: Determine the number of moles in g of copper.
1) Given
2) Use molar mass
1 mol Cu =
63.55 g Cu
75.92 g Cu x
1.195 mol Cu
3) Solve, round answer using sig.figs

5. 1) Given 2) Use molar mass 58.44 g NaCl= 1 mol NaCl 154 g NaCl
Example: Find the mass of 2.64 mole of sodium chloride.
1) Given
2) Use molar mass
58.44 g NaCl=
1 mol NaCl
154 g NaCl
2.64 mol NaCl x
1 Na = g
1 Cl = g
3) Solve, round answer using sig.figs

6. Converting Avogadro’s Number/ moles
6.02 x 1023 ?
6.02 x 1023 ?
1 mole ?
? = type of particle

7. Example: Convert 2.66 mol of a sodium into atoms.
1) Given
2) Use Avogadro’s #
6.02 x 1023 atoms Na =
1mol Na
2.66 mol Na x
1.60 x 1024 atoms Na
3) Solve, round answer using sig.figs

8. 2) Use Avogadro’s # 1) Given 2.54 x 1022 ions Fe3+ x
Example: How many moles are 2.54 x iron(III) ions?
2) Use Avogadro’s #
1) Given
1 mol Fe =
6.02 x 1023 ions Fe3+
2.54 x 1022 ions Fe3+ x
mol Fe3+
3) Solve, round answer using sig.figs