1. DO NOW! On Notebook Paper…
How many liters are in 0.32 moles of Argon gas?
How many atoms are in 292 grams of CO₂?

2. Unit: Chemical Quantities
Notes
Unit: Chemical Quantities
Calculating Percent Composition

3. After today, you will be able to…
Calculate percent composition for various compounds

4. Percent Composition ____________
Indicates the makeup of a substance based on mass. (Example: 50% carbon by mass)
____________
Mass of element
x 100
% element =
Mass of compound

5. Example: What is the % Lithium in Li2O?
13.88
+16.00
29.88
13.88
%Li = _______
x 100 =
46.45% Li
29.88

6. Example: What is the % of each element in Ba3(AsO4)2?
411.99
149.84
689.83
%Ba = ______
411.99
x 100 =
59.723% Ba
689.83
%As = ______
149.84
x 100 =
21.721% As
689.83
%O = ______
128.00
x 100 =
18.555% O
689.83

7. Example: What is the % of each element in Ba3(AsO4)2? (#2 on WS)

8. Time to Practice! Complete WS
HOMEWORK:
Time to Practice! Complete WS

9. 25 points
50 points
100 points
% H in CH4
% O in K3(PO4)
%C in Mg(C2H3O2)2
% Na in NaCl
% H in H(NO2)
% N in Be(CN)2