1. Topic: Percentage Composition
Sugar C12H22O11
is made up of 42.1 % carbon, 6.4 % Hydrogen and 51.5% oxygen. Draw a pie- graph representation of this

3. Percent Part X 100% Whole Percent Composition by mass =
Mass of element
X 100
Mass of compound

4. Percent Compositions can help us identify unknown pure substance

5. Percent Composition of H2O
% H = 2g x 100 = %
18g
% O = 16.0g x 100 =88.9%
18.0g
100.0%
H = 2x 1 = 2g
O = 1 x 16=16g
18g

6. Percent Composition of C6H12O6
C = 6 x 12 = 72g
H = 12 x 1 = 12g
O = 6 x 16 = 96g
______
180g
/180 x 100 =
40.0%
/180 x 100 =
6.7%
53.3%
/180 x 100 =

7. Please NOTE: Sum of individual element %’s must add up to almost 100%
usually works out exact if round to 2 decimal places