1. Pure Substances Elements
Composed of one type of atom
Metal, Non-metal or Metalloid
Simplest type of matter that retains
characteristic properties

2. Pure Substances Compounds
A combination of two or more elements
Properties differ from those of component elements
Separated by chemical means

3. Mixtures Heterogeneous
Has one or more visible boundaries between the components
Composition is not uniform
Some boundaries may only be seen with a microscope ie. Blood, milk

4. Mixtures Homogeneous
No visible boundaries because components are mixed as individual atoms, ions or molecules
Composition is uniform on a molecular level
Alloy- steel, a combination of Fe and C
We cannot tell visually whether an object is a substance or a homogenous mixture

5. Filtration
Separates the components of a mixture on the basis of differences in particle size
Usually a heterogeneous mixture
Most common method is to use filter paper to separate the components. The remaining liquid, after separation, is the filtrate.

6. Separation techniques
Filtration – uses a porous barrier to separate a (non-dissolved) solid from a liquid

7. Distillation
Separates components through differences in volatility : used for homogenous mixtures
The mixture is heated until the substance with the lowest boiling point becomes a vapor that can be condensed into a liquid and collected.
If the distillation is controlled ,you can separate substances that differ by a few degrees.

8. Distillation – separates liquids based on their boiling points

9. Crystallization Based on differences in solubility
When a solution contains as much dissolved substance as it can possibly hold it has reached the saturation point
The addition of even a tiny amount causes the dissolved substance to come out and collect as crystals

10. Crystallization – a method of extracting dissolved solids from a solution

11. Chromatography Based on differences in solubility
The separation is based on the various components of the mixture spreading out through the paper at different rates
Components with the strongest attraction for the paper move slower (highly soluble)

12. Chromatography – separates components of a mixture based on how well it can travel across a particular material

13. Law of Conservation of Mass
Mass is neither created nor destroyed it just changes form:
Mass reactants = Mass products

14. A 10. 0 g sample of magnesium reacts with oxygen to form 16
A 10.0 g sample of magnesium reacts with oxygen to form 16.6 g of magnesium oxide. How many grams of oxygen reacted?
What part of the reaction is a compound?

15. From a laboratory process designed to separate water into hydrogen and oxygen gas, a student collected 10.0 g of hydrogen and 79.4 g of oxygen. How much water was originally involved in the process?

16. If 19. 9 grams of copper are burned in air to produce 25
If 19.9 grams of copper are burned in air to produce 25.0 grams of copper oxide, what is the mass of oxygen from the air that is needed?

17. Law of Conservation of Mass
Applies to compounds:
The mass of a compound is equal to the sum of the masses of the elements that make up that compound

18. 20.00 g of sugar
Carbon
Hydrogen
Oxygen
sum
Find Percent by Mass of each element:

19. Law of Definite Proportions
percent by mass = mass of element x 100 mass of compound

20. Carbon: Hydrogen: Oxygen: 8.44 g C X 100 = 42.20 % 20.00 g sucrose
1.30 g H X = %
Oxygen:

21. Analyze 500.0 g sucrose Carbon 211.0 Hydrogen 32.5 Oxygen 256.5
sum

22. A 78. 0 g sample of an unknown compound contains 12. 4 g of hydrogen
A 78.0 g sample of an unknown compound contains 12.4 g of hydrogen. What is the percent by mass of hydrogen in the compound?

23. What is the percentage by mass of I if 4. 07 g reacts with 10
What is the percentage by mass of I if 4.07 g reacts with g of II to form a compound of mass g? Also, calculate the percentage by mass of II in the compound.