1. Percent composition
C-notes on page 64

2. Example: Find the % composition of all of the elements within a glucose molecule using the molecules molar mass. You will have to know how to do this to complete future objectives.
Glucose: molecular formula = C6H12O6
(will be given information)
Find the molar mass of the compound
Find the % of each element with in the compound:
element mass x 100 = %composition
molar mass

3. Glucose: molecular formula = C6H12O6
molar mass =
(12.01 g/mol x 6) + (1.01 g/mol x 12) + (16.00 g/mol x 6)
= g/mol g/mol g/mol
= g/mol

4. % composition of carbon
72.06 g/mol = x 100 = 39.99% carbon
g/mol

5. % composition of hydrogen
= g/mol = x 100 = 6.73% hydrogen
g/mol

6. % composition of oxygen
= g/mol = x 100 = 53.28% oxygen
g/mol

7. Check your answer
The end result is that all parts of the compound should equal 100% (or very, very close due to rounding issues)
53.28% % % = 100%

8. Practice problems for pg 64 will be part of notes
Write the chemical formula
Find the molar mass
Find % composition of each element in compound
Sodium chloride
Aluminum hydroxide
Ammonium phosphide
Summarize notes and complete practice for stamp

9. Bubble gum lab This will be turned in for a grade.
You will need 5 pieces of unchewed gum.
We will be going to the lab. While in the lab you need to do the pre lab and steps #1 and #2.
DO NOT CHEW THE GUM YET!!!!!!!!!