aim: how can we use physical and chemical properties to separate matter. objectives: (swbat)...
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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)
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
Capillary action
• Is the ability of a liquid to flow in narrow spaces without the assistance of, and in opposition to external forces like gravity. The effect can be seen in the drawing up of liquids between the hairs of a paint-brush, in a thin tube, in porous materials such as paper, or in a cell. It occurs because of inter-molecular attractive forces between the liquid and solid surrounding surfaces.
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
No chemical change occurs when salt water is distilled.
Saltwater solution(homogeneous mixture)
Distillation(physical method)
Salt
Pure water