1. Pure Substances and Mixtures

2. Review from Last Class…
Correct Side 2 of Pure Substances worksheet (702)
Elements Project
*Pass Back Corrected Assignments/Quizzes
*Missing Assignments Reports (702)

3. Mixtures

4. Mixtures
Two or more pure substances or elements NOT chemical combined (Physically mixed)
No reaction between the substances

5. Mixtures Cont’d
Mixtures can be separated into their components by chemical or physical means
The properties of a mixture are similar to the properties of its components.

6. Mixtures
Homogeneous Mixture: mixtures that have two or more components that appear like only ONE substance (Solutions, alloys etc)

7. Solutions
Solutions are homogeneous mixtures in which two pure substances are mixed together
They have the following properties
Well-mixed (uniform) – single phase
Homogeneous
Transparent
cannot be separated by filtering
do not separate on standing

8. States of matter in solution
Example of solutions
gas in gas
air ( N2, O2 , Ar, CO2 , other gases)
gas in liquid
soda pop (CO2 in water)
liquid in liquid
gasoline (a mixture of hydrocarbon compounds)
solid in liquid
Filtrated sea water ( NaCl and other salts in water)
gas in solid
H2 in platinum or palladium
liquid in solid
dental amalgams (mercury in silver)
solid in solid
alloys ( brass, (Cu/Zn), sol-der (Sn/Pb), Steel (Fe/C ))

9. Mixtures
Heterogeneous Mixture: mixtures that have two or more components that remain VISIBLE even after they are mixed (Ex: Colloids, suspensions)

10. Heterogeneous Mixtures
The components are not evenly distributed
Has two or more phases that are usually detectable (parts you can see)

11. Colloids Non-transparent (can’t see through) Non-Uniform
Large Particles scattered throughout
Cloudy

12. Suspensions
Suspension: system does not stay stable and settles after resting for period of time
Aerosol: A suspension of liquid droplets or fine solid particles in a gas
Examples of Suspensions
Mud or muddy water, is where soil, clay, or silt particles are suspended in water.
Flour suspended in water, as pictured to the right.
Paint
Chalk powder suspended in water.
Dust particles suspended in air.
Algae in water
Milk of Magnesia

13. Heterogeneous or Homogeneous?
Lemonade
Paint
Soda with Carbonation
Salt water
Granola Cereal
Ketchup
Fruit Yogurt
Chicken noodle Soup
Beach Sand
Salad
Salted and Buttered Popcorn
Milk
Crayons with paper wrappers
Chocolate chip Cookies
Jelly Beans

14. Tyndall Effect
A test used to check whether a mixture is homogenous or heterogeneous
Tyndall effect: You can see the light pass through a colloid or suspension (heterogeneous mixtures) because the particles scatter light
Light will not be seen through homogenous solutions

15. Pure Substances and Mixtures Worksheet
Complete for homework and hand in Wednesday December 9th

16. Mixtures Lab
Using basic observation, magnifying glass microscopes, and a light, identify whether each liquid is a homogeneous or heterogeneous mixture
Rules of lab?