1. Chapter 10: Chemical quantities
Honors Chemistry
Chapter 10: Chemical quantities

2. The Mole How to determine quantity of matter Molar mass Molar volume
Counting: mole…a number of convenience
Mass: grams/mole
Amu: 1/12 of a carbon-12 atom
Molar mass
Mass of one mole
Sum of atomic masses of all atoms in a formula unit (ionic cpd) or
molecule (covalent cpd)
Molar volume
Volume of one mole at STP =22.4L

3. Percent composition Think: pie chart…all parts much equal 100%
Convert to 100 grams
Then, divide by molar mass of each element to get moles
Divide by lowest number of moles to get mole ratio
Make sure whole numbers
Does it add to 100%?
Empirical formula: lowest ratio of atoms in a molecule/formula unit
May or may not be molecular formula