1. Do Now & Agenda Turn in Beer’s Law Lab if you did not do so last class
Work on “Chem Phys Properties”
Today:
Chemical and Physical Properties: get stamped
Separation Techniques
Plan Separation Challenge
Unit 2 Test FRI 10/21 (B), MON 10/24 (A)
All missing work, corrections, and extra credit due by Test Day!

3. Definitions
Physical Property=a property of matter that can be measured or observed without changing the chemical composition of the substance
Ex: mass,
melting and boiling point,
Solubility (ability to dissolve in something)

4. Definitions
Chemical Property=a property of matter that can only be measured or observed by changing the chemical composition of the substance
Ex:
Flammability
Reactivity (whether the substance reacts with another substance)

5. Practice
Identify the following as either physical properties (P) or chemical properties (C) 1. ____blue color 2. ____density 3. ____solubility 4. ____reacts with acid 5. ____volume 6. ____melting point 7. ____reacts with water to form a gas 8. ____hardness P P P C P P C P

6. Intensive vs. Extensive Properties
Intensive Property: does NOT depend on how much of the substance there is
Extensive Property: depends on how much of the substance there is

7. Recall…
Mixture=a combination of 2 or more substances that you can physically separate into their individual parts without changing what they are.
Mixtures can be separated based on their physical properties (ex: boiling point, solubility, size)

8. Filtration
*separation based on different state of matter or particle size a technique that allows you to separate a heterogeneous mixture by catching the solid (undissolved particles) on the filter

9. Filtration

10. Filtration Examples Around the House

11. Evaporation takes advantage of differences in boiling point
can be used to separate homo- or heterogeneous mixtures
Downside: liquid components of mixture are lost to air through evaporation

12. Distillation takes advantage of differences in boiling point
can be used to separate homogeneous or heterogeneous mixtures
Superior method to evaporation because all components can be isolated and retained.
The liquid with the lower boiling point collects in this flask
Mixture of 2 liquids is placed in a flask over a heat source. The liquid with the higher boiling point stays in this flask

13. Centrifuge Separates a mixture based on differences in density
Amount of separation depends on speed of centrifuge
Must be followed by filtration or decanting
Separates heterogeneous mixtures only!

14. Decanting
Takes advantage of differences in states of matter and/or density
A crude separation technique for heterogeneous mixtures.

15. Chromatography
Chromatography is a technique that allows you to separate a homogeneous mixture based on size and polarity
*polarity = level of attraction towards another substance
Separate
Mixture
Components

16. How Chromatography Works
Chromatograhy paper
Developing
chamber
Place TLC plate into
Small samples of substances
(liquid)
Chromatography separates the components of a mixture based on how attracted the individual components are to the chromatography paper vs. the liquid

18. Gas Chromatography
Relies on the fact that different compounds dissolve to different extents in a particular liquid
Also can be used to separate based on size

19. Gas Chromatography

20. Column Chromatography
Separates the components of a mixture based on the differences in size
The smallest molecules exit the column first
The largest molecules exit the column last
Separation can also be based on polarity (attraction) to the material in the column

21. Other Techniques…
Sifting
magnetism

23. Separation Challenge
Write a procedure for how you would separate a mixture of sand, salt, and iron into 3 separate containers
Procedure must be DETAILED, use complete sentences. Indicate what materials you need!
You will carry out this procedure next class