ACTION PLAN OF G.SCIENCE BY Ms. FAIZA RANI DA MHS PHASE - IV

SOLUTIONS, SUSPENSIONS AND COLLOIDS

LONG TERM GOALS Adopt 21st century teaching approaches to enhance student’s interest in Science particularly in Chemistry.

ANALYSIS EVALUATING CREATING SHORT TERM GOALS At the end of the session students will be able to: ANALYSIS Distinguish different types of mixtures with the help of a chart. EVALUATING Compare the solutions and suspensions and evaluate them. CREATING Compile the different examples of mixtures from everyday life in the form of a project.

INSTRUCTIONAL STRATEGIES TOPIC 21st CENTURY APPROACH 21st CENTURY SKILLS TECHNIQUE SOLUTIONS, SUSPENSIONS AND COLLOIDS Listening and Speaking skills Questioning skills Giving direction skills Communication skills Creativity skills Critical thinking Self direction PROJECT

CONTENTS Solution and its components Aqueous, Diluted and Concentrated Solutions Suspensions Difference between Solutions and Suspensions Colloids Emulsions

How is a Solution defined? “The homogeneous mixture of two or more substances is called solution.” Homogeneous mixture means, the color, density, appearance and other physical and chemical properties are the same in every part of the solution.

Components Of Solution SOLUTE SOLVENT (dissolved material) (dissolving medium) e.g, salt, sugar etc e.g, water, vinegar etc

How is a solution prepared?

Solute (salt) Solvent (water) A Salt Water Solution Solute (salt) Solvent (water)

What is meant by Aqueous solution? Aqua – water Solution in which water is used as solvent. For e.g, Aqueous solution of sugar is prepared by dissolving sugar in water.

What is meant by diluted and concentrated solution? If less solute is dissolved in a solvent, then it is a diluted solution If more solute is dissolved in the solvent, it is called concentrated solution

“A mixture of an insoluble solid in a liquid is called suspension.” What is a Suspension? “A mixture of an insoluble solid in a liquid is called suspension.” Suspensions are heterogeneous mixtures. Heterogeneous mixture means the physical and chemical properties are different throughout the mixture.

Examples of suspension Chalk dissolved in water Sand dissolved in water Flour in water after settling suspension particles settle out water molecules clay particles

[solution] [suspension] [pure substance] [colloid] [After passing through a muddy pond, the water in a stream contains dirt particles. Which of the following describes the stream?] [solution] [suspension] [pure substance] [colloid]

Difference between Solution and Suspension Homogenous mixture All solute particles are evenly dissolved. Solutions are clear. Heterogeneous mixture Solute particles are settled down. Suspensions are cloudy.

Difference between Solution and Suspension The dissolved solute particles can’t be separated by physical method. Light rays do not scatter on passing though solution. The insoluble solute particles can be separated by filtration. Light rays scatter on passing through the suspension.

COLLOID “A mixture which behaves like something in between solution and suspension is called Colloid.” Intermediate between a homogenous mixture and heterogeneous mixture. Solute particles are mixed in such a way that they remain evenly distributed without settling down like a solution but cloudy like a suspension. Like suspensions, light rays scatter on passing through colloids. (Continued)

15.3 Particles in colloids and suspensions reflect or scatter light in all directions. Solutions do not scatter light. The path of light is visible only when the light is scattered by particles. a) Fog or mist is a colloid and thus exhibits the Tyndall effect. b) Particles in colloids and suspensions reflect or scatter light in all directions. Solutions do not scatter light.

Examples of colloid Cheese Toothpaste Ice cream etc

[A colloid can be separated by filtration?] True False

EMULSIONS “An emulsion is made up of minute droplets of oil suspended in a liquid.” If you mix oil and water and shake them a cloudy suspension is formed. Let the mixture rest and the oil and water will separate. (A) (B)

What is an Emulsifying agent? An emulsifying agent (emulsifier) is any substance that keeps the parts of an emulsion mixed together. For example if we mix oil and water a suspension will form that over time separates. But now, if we add a few drops of liquid soap and shake the mixture the oil and water will stay mixed much longer.

Examples of Emulsions Margarine Mayonnaise etc

OVERVIEW A solution is a homogenous mixture which contains two or more solutes dissolved in a solvent. The physical and chemical properties are the same in every part of the solution. Light rays do not scatter on passing through the solution. A suspension is a mixture of an insoluble solid in a liquid. The composition of suspension is not same throughout the mixture. Light rays scatter on passing through the suspension, means light passing through the suspension will be scattered by the particles so that the light beam is visible. Continued

The solution in which water is used as a solvent is called aqueous solution. A solution in which the amount of dissolved solute is very small as compare to solvent is called Diluted solution. While, those solutions which contain a considerable amount of solute in a given amount of solvent are called concentrated solutions.  Those mixtures which behave like something in between solution and suspension are called colloids. Such as Ice Cream, Tooth paste, Cheese etc  An emulsion is made up of minute droplets of oil suspended in a liquid. Such as oil in water.

ACTIVITY

APPLICATION Q: Define solution and its components with examples. Q: Define the following; Aqueous solution Emulsion Colloid Q: Write down the difference between solutions and suspensions. Do visit the following web site…. http://www.youtube.com/watch?v=q96ljVMHYLo

QUIZ

QUIZ Marks: 10 Q: 01 Fill in the blanks: (03) 1. If the mixture separates upon standing, the mixture is a ______________. 2. If the mixture does NOT separate upon standing and does not scatter the light rays, the mixture is a _____________________.  3. If the mixture does NOT separate upon standing and scatters the light rays, the mixture is a _________________________.  Q: 02 Define Emulsions and Colloids with examples. (02)  Q: 03 Choose the correct answer: (05) 1. In a solution the substance that is being dissolved is called the__________________ a) Solvent b) Emulsifier c) Solute d) Filtrate  2. An emulsion is always between____________________ a) Two solids  b) Two liquids c) Two gases d) A solid and liquid  3. What is one property of a suspension that is different from that of a solution or a colloid? a) If left to rest, the particles of a suspension will settle out. b) The particles of a suspension reflect light. d) Suspensions are colorless c) A suspension is always clear 4. An example of a solution is _____________________ a) Sugar and water b) Sand and water d) Ice Cream c) Milk Continued  

5. What factor distinguishes a suspension from a colloid 5. What factor distinguishes a suspension from a colloid? a) Light reflects off the particles of a suspension b) The particles of a suspension will sink out if left over time to rest c) Suspensions are clear d) Suspensions cannot be filtered 6. An example of an emulsifying agent would be_________________________. a) Oil b) Soap c) Water d) Salt 7. An example of a suspension is_______________________. a) Chalk dissolved in water b) Butter c) Salt dissolved in water d) Oil and water 8. A solution that contains less amount of solute is called __________________________. a) A Diluted solution b) A concentrated solution c) An Aqueous solution d) None of the above 9. Which of the following is not a colloid? a) Tooth paste c) Flour in water d) Sand in water 10. Complete the following table by writing ‘YES’ or ‘NO’: Type of mixture Settles out? Scatters light? Suspension Colloid Solution

REFERENCES Books: Lower Secondary Science 2 by Tho Lai Hoong School Chemistry by Dr. Saifuddin Internet Sources: http://www.slideshare.net/hmsoh/ch08-solutions-suspensions http://www.slideshare.net/jbishopgcms/solutions-suspensions-and-colloids http://www.youtube.com/watch?v=q96ljVMHYLo http://www.slideshare.net/joeltoh/solutions-and-suspensions-i http://woodstown.org/ACS/resources/ac/ch6/act3.pdf http://galileo.phys.virginia.edu/education/outreach/8thgradesol/MixSoln.htm http://www.suite101.com/content/simple-science-experiments-a32509