St. George's College
Subject: 8th CHEMISTRY
Class: Common Separation Techniques
Teacher's notes
Objectives
Vocabulary Link and Learn
Date: August 17th
Prepared by
In‐Class Survey
2009 1
8th Milton A ‐ Common Separation Techniques Name
Oral Intervention
Sergio María Fernanda Alejandra Almendra Anna Paula Sandra E‐C Maia María Belén Alfredo Kinley Arianne Sandra M. Fiorella Rodrigo Giulia Jaime Stefano Bruno
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8th Milton Alpha ‐ Common Separation Techniques Name
Oral Intervention
Marcelo Antonella Paulo Alejandro Brenda Diego Gabriel Valeria Cristina Giuliana Joshua María Gracia Gonzalo N. Paolo Gonzalo R. Giorgio Nicolás María Claudia
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Let's remember previous learned concepts...
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Mixtures
• A Mixture contains more than one substance. • Each substance in a mixture retains its own chemical identity and properties. • Most of the matter we encounter consists of mixtures of different substances. • Whereas pure substances have fixed compositions, the compositions of mixtures can vary. • Some mixtures, do not have the same composition, properties, and appearance throughout the mixture. • Such mixtures are heterogeneous (For example: such as sand, rocks, and wood). • Mixtures that are uniform throughout are called homogeneous. Combinations
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Combination
Non窶信ixture
Solution
Mixture
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Properties of Matter • Every substance has a unique set of properties, or characteristics that allow us to recognize and distinguish one substance from another. • Properties can be: physical or chemical. • Physical properties can be measured without changing the identity and composition of the substance. For example: Color, odor, density, melting point, boiling point, hardness, etc. • Chemical properties describe the way a substance may change or react to form other substances. For example: Flammability.
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Types of Mixtures • A Solution is a special kind of mixture, where mixing occurs at the molecular level. • Thus, all solutions are mixtures, but not all mixtures are solutions. • Mixtures can be made from any number of components, and these components can come from any of the three states of matter: solid (S), liquid (L), or gas (G). • So, if we just consider binary (two‐component) mixtures, then we can have mixtures of six types: S/S, S/L, S/G, L/L, L/G, G/G. • Moreover, these combinations could (at least in principle) be either physical mixtures or solutions. 8
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Liquid/Solid Mixtures Physical Mixtures • Mud: mixture of water and dirt. Does dirt dissolve in water? • Skim Milk: mostly water, with very small particles ("micelles") of protein (casein). Casein scatters light, therefore the white color. When milk is coagulated, casein forms cuddles. • Latex paint: typically 70% water, 30% polymer. This polymer scatters light, so gives it a white color. Latex paint is formulated to avoid coagulation.
Solutions • Kool‐Aid: A mixture of water (liquid), sugar (solid), and flavor (crystals or powder). Typically clear (see‐through) although colored. • Seawater: a mixture of water (liquid) and a variety of solid minerals (sodium chloride, etc). Seawater is also clear, making it a typical solution.
Suspensions • A solid substance suspended, and not dissolved in water, but small enough not to be seen forms a Suspension.
Recommended: Find out about: emulsion, gel. 10
New knowledge beginning......
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Separation Techniques • In order to separate substances, mixtures or combinations, different techniques can be used, depending on the nature of the substance, mixture or combination, but also considering the properties of the same. • Some substances require simple separation techniques, because is not necessary to break down chemical bonds, or change the chemical properties of the original substance. • So, when the separation techniques use only physical properties, then the separation techniques are simple to apply, although laborious in some cases. • Separation of substances by breaking chemical requires the use of more complex techniques.
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Physical Methods DECANTATION Quick separation method to separate a S/L mixture, with a heavy solid.
FILTRATION Especially used for separating suspensions. The mixture is poured into a funnel, where a filter paper avoids the pass of the solid particles larger than the holes from the filter paper.
CENTRIFUGATION Used to separate small amounts of suspension. The S/L mixture is poured in a tube and spinned very fast in a centrifuge machine. EVAPORATION Used to separate solutions, whose solute has tiny particles. the solution is heated to evaporate the solvent and leave the solute (solid) behind. DISTILLATION When an evaporated substance is cooled down, it condenses into its liquid form. So, Distillation=Evaporation+Condensation. CHROMATOGRAPHY Process through which a solution displaces with different speeds over a special type of paper, separating different substances. Depends on two things: solubility of the substance in the solvent, and the adsorption of the substance in the filter paper. 14
RETENTATE
PERMEATE
Chromatography
Distillation Evaporation
Centrifugation
Filtration
Decantation
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Chromatography Distillation
Evaporation
Centrifugation
Filtration
Decantation
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ASSIGNMENT
NOTEBOOK 1. Complement the Class by finding out and writing in your notebook, the definitions, properties and examples of the separation techniques by chemical methods: 2. Deadline: • Group A: Monday, August 24th. • Group Alpha: Monday, August 24th. 3. Criteria of Evaluation: • (5 p) Compliance with the Deadline • (5 p) Quality of Information • (5 p) Organization‐Presentation • (5 p) Optional: Make a Web Diagram having MIXTURES as the central idea.
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Resources Used Slide (Group)
Description
Resource
Origin
G1 ‐ 2
Image
Milton
http://bit.ly/XQqEw
G1 ‐ 3
Image
Milton
http://bit.ly/XQqEw
G1 ‐ 4 Animation Idea
Notebook Gallery
G1 ‐ 6
Images
Mixtures Nuts Lemonade
http://bit.ly/ivINE http://bit.ly/rsVRv http://bit.ly/4acyHs
G1 ‐ 9
Image
Mixtures
http://bit.ly/3MnSlj
G1 ‐ 11 Animation Check this out
Notebook Gallery
G1 ‐ 13 Images
Separation Tools
http://bit.ly/2wa6TA
G1 ‐ 15 Images
Decantation Filtration Evaporation
http://bit.ly/sVWyP http://bit.ly/FTqT http://bit.ly/1Mxshq
G1 ‐ 16 Images
Centrifugation Distillation Chromatography
http://bit.ly/2UCpse http://bit.ly/BdEvZ http://bit.ly/32RPxw
G1 ‐ 15 G1 ‐ 15
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Teacher's Notes This class has been designed to cover the topics of Common Separation Techniques from Monday August 17th till Friday August 21st. For further knowledge about this topic: 1. Conduct a thorough search under the topic: Common Separation Techniques on the Web, books and magazines. 2. If findings are not specific, ask your teacher for suggestions.
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Objectives • Identify and apply the most common separation techniques for mixtures and combinations.
Note: All, or most, of the objectives will be covered during class time, however the student must be responsible for those objectives not covered or concluded.
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• • • • • • • • • • •
Vocabulary Decantation: Filtration: Centrifugation: Evaporation: Crystallization: Distillation: Fractional distillation: Sublimation: Chromatography: Melting Point: Boiling Point:
Note: Most of the vocabulary words will be covered during class time, however the student must be responsible for those words not covered or concluded.
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Link and Learn You can visit the following websites to improve your understanding on the present topic: • • • • • • • •
http://library.thinkquest.org/11430/research/techniques.htm http://bit.ly/17E1ZK http://www.webelements.com/ http://www.chem1.com/acad/webtext/atoms/atpt‐6.html#SIZE http://www.dayah.com/periodic/ http://science‐learning2009.wikispaces.com http://learningandscience.blogspot.com http://libraryatstgeorge.blogspot.com
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Prepared by
Gerardo LAZARO Science Lead Teacher Email: glazaro@sanjorge.edu.pe Wiki: http://science‐learning2009.wikispaces.com Blog: http://learningandscience.blogspot.com Twitter: http://twitter.com/glazaro
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SURVEY If you want to contribute in improving your Chemistry class, click in the survey link:
Term III ‐ 8th A ‐ Class 2 Term III ‐ 8th Alpha ‐ Class 2
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Term III Class 2 Common Separation Techniques
Grade: Subject: Date:
8th Grade Chemistry A August 17th, 2009
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What was your UNDERSTANDING of the topic: "Common Separation Techniques"
1
A
I understood 25% of the whole topic
B
I understood 50% of the whole topic
C
I understood 75% of the whole topic
D
I understood 100% of the whole topic
E
I didn't understand the class
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2
What was your level of EFFORT to understand the topic?
A
My effort level was 25%
B
My effort level was 50%
C
My effort level was 75%
D
My effort level was 100%
E
I didn't put any effort
27
3
What RESOURCES helped you understand the topic? A
Text
B
Images
C
Animations
D
Videos
E
Teacher's Speech
F
None
G
Other
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4
How does the SMART Board help you understand the topic?
A
It helps me visualize concepts
B
It helps understand difficult concepts
C
Touching things helps me learn
D
Interacting with the information makes it easier to understand
E
I prefer less effects or audiovisual resources
F
It doesn't really help much
G
I don't like it
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Term III Class 2 Elements, Mixtures and Solutions
Grade: Subject: Date:
8th Grade Chemistry Alpha August 17th, 2009
30
What was your UNDERSTANDING of the topic: "Common Separation Techniques"?
1
A
I understood 25% of the whole topic
B
I understood 50% of the whole topic
C
I understood 75% of the whole topic
D
I understood 100% of the whole topic
E
I didn't understand the class
31
2
What was your level of EFFORT to understand the topic?
A
My effort level was 25%
B
My effort level was 50%
C
My effort level was 75%
D
My effort level was 100%
E
I didn't put any effort
32
3
What RESOURCES helped you understand the topic? A
Text
B
Images
C
Animations
D
Videos
E
Teacher's Speech
F
None
G
Other
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4
How does the SMART Board help you understand the topic?
A
It helps me visualize concepts
B
It helps understand difficult concepts
C
Touching things helps me learn
D
Interacting with the information makes it easier to understand
E
I prefer less effects or audiovisual resources
F
It doesn't really help much
G
I don't like it
34