Post on 12-Feb-2016
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AIM: How can we use physical and chemical properties to separate matter. OBJECTIVES: (SWBAT)
1.Identify basic physical properties used to separate samples of mixtures.
2.Understand and describe how these physical properties are used to separate mixtures.
3.Design appropriate methods to separate unknown mixtures.
DO NOW: List 6 physical properties that may be useful in the separation of mixtures.
Electrolysis
*Must add acid catalyst to conduct electricity
*H1+
water oxygen hydrogen
“electro” = electricity “lysis” = to split
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 32
Water
Hydrogengas forms
Oxygengas forms
ElectrodeSource ofdirect current
H2O(l) O2 (g) + 2 H2 (g)
Water hydrogen + oxygen
= hydrogen atom = oxygen atom
Methods of Separating Mixtures
1.What is a filter?
2.What type of mixture is separated by filtration?
3.Define filtrate:
4.Define residue:
5.What physical properties are used to separate substances by filtration?
6.Give examples of 3 mixtures that can be separated by filtration.
1. FILTRATION
Filtration separates
a liquid from a solid
Mixture ofsolid andliquid Stirring
rod
Filtrate (liquidcomponentof the mixture)
Filter papertraps solid
Funnel
2. CHROMATOGRAPHY1. What physical properties are used to separate mixtures by
chromatography?
2. What is capillary action?
3. Why do the components separate on the chromatography paper?
4. Give 2 examples of mixtures that can be separated by this method.
Chromatography• Tie-dye t-shirt
• Black pen ink
• DNA testing– Tomb of Unknown Soldiers– Crime scene – Paternity testing
Paper Chromatography
Ion chromatogram of orange juice
time (minutes)
dete
ctor
re
spon
se
0 5 10 15 20 25
Na+
K+
Mg2+ Fe3+
Ca2+
The solution is boiled and steam is driven off.
3. DISTILLATION
How can you separate a sand-saltwater mixture.
Separation of a sand-saltwater mixture.
Salt remains after all water is boiled off.
No chemical change occurs when salt water is distilled.
Saltwater solution(homogeneous mixture)
Distillation(physical method)
Salt
Pure water
Setup to heat a solutionRing stand
Beaker
Wire gauze
Ring
Bunsen burner
EVAPORATION