1. Converting Between Moles and Mass
Millicent McAlpin
May 22, 2013
Chemistry honors

2. THE MOLAR MASS Mole: a unit used in counting
- According to Avogadro’s number =6.02 x 10^23
Molar Mass: is the same is the atomic number of an element on the periodic table.
Mass of 1 mole:
-Na= 23
-F= 19
Mole is always equal to…..
Mass of one mole of a substance

3. MOLAR MASS CONVERSION
To convert between moles and Mass we use MOLAR MASS.
MASS =
Moles x molar mass= mass
10g Na + 5g/1 mol = 2 mol Na
MOLES =
Mass + molar mass = moles
15g Na + 5g/1 mol = 3 moles Na

4. SOME EXAMPLES!!!
How many moles of Sodium Oxide Na2O are there in a sample weighing 40 grams.
Equation: mass/ molar mass = moles
Mass:
40 moles
Molar mass of Na2O =
51/g Na2O
Set up the equation!
40 g Na2O / 51 g = 0.78 moles Na2O

5. SOME EXAMPLES
How many grams of water, H2O are there in a sample of 20 moles
Equation: moles x molar mass = mass
Moles:
- 20 moles
Molar mass of H2O =
-18 g H2O
Set up equation!
20 moles H2O x 18g = 360 g H2O

6. TRY IT ON YOUR OWN
How many moles of hydrogen peroxide is there in a sample weighing 500 grams
Equation: mass/ molar mass
500 g / 32 g H2O2 =
15.62 mole H2O2