1. Do Now Take out Molarity & Chem/Phys Properties WS from Friday
Unit 2 Test FRI 2/19
Do Now:
Get into lab groups. Calculate the Molar Mass of your given substance.

2. Solutions Mini-Lab

3. 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)

4. 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

5. Filtration

6. Filtration Examples Around the House

7. 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

8. 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

9. 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!

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

11. 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

12. 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

14. 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

15. Gas Chromatography

16. 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

17. Other Techniques…
Sifting
magnetism

18. TEST CORRECTIONS Separate sheet of paper
Question number + Correct Answer
YOU NEED TO EXPLAIN/SHOW WHY THE ANSWER IS CORRECT
You can earn back up to half the points that you lost