Lesson plans for teachers, Lecture notes of Environmental science

Download Lesson plans for teachers and more Lecture notes Environmental science in PDF only on Docsity! 1 PART 2 D.A.V INTERNATIONALSCHOOL,AHMEDABAD LESSONPLAN Class-IX Subject: Science Chapter name: Is Matter Around Us Pure Total no. of periods:6 Prepared by Haimonti Banerjee CONCEPT MAP (FOR THE COMPLETE CHAPTER) . MIXTURE HOMOGENEOUS SOLUTION (finding out the concentration of the solution) HETEROGENEOUS SUSPENSION COLLOID (different types of colloids with common examples) DIFFERENT METHODS OF SEPARATING A MIXTURE SEPARATION OF COMPONENTS OF A MIXTURE OF SOLID IN LIQUID FILTRATION EVAPORATION CRYSTALLISATION CENTRIFUGATION SEPARATION OF COMPONENTS OF A LIQID - LIQUID MIXTURE. SEPAPATION OF IMMISCIBLE LIGUIDS BY SEPARATING FUNNEL SEPARATION OF COMPONENT LIQUIDS IN A MISCIBLE LIQUID MIXTURE DISTILLATION FOR 2 COMPONENTS FRACTIONAL DISTILLATION FOR MORE THAN 2 COMPONENTS SEPARATION OF COMPONENTS OF SOLUTES THAT DISSOLVE IN SAME LIQUID USING CHROMATOGRAP HIC SEPARATION SEPARATION OF SOLID COMPONEN TS BY SUBLIMATI ON DEPENDING ON THE CONSTITUENT PARTICLES ANYTHING AROUND US MATTER PURE SINGLE TYPE OF PARTICLE ELEMENT COMPOUND MIXTURE MORE THAN ONE TYPE OF PARTICLES PRESENT IN VARIED PROPORTION PART 1 PART 3 2 •INCREASE OF PRESSURE •DECREASE OF TEMPERATURE AIR FRACTIONAL DISTILATION LIQUID AIR •NITROGEN OUT •ARGON OUT LIQUID OXYGEN PURE SUBSTANCES COMPOUNDS ELEMENTS METALS METALLOIDS NON-METALS PHYSICAL AND CHEMICAL CHANGES PART4 • TO BE ABLE TO DISTINGUISH AND IDENTIFY THE CHANGES OCCURING AROUND US AS PHYSICAL AND CHEMICAL. Learning Objectives ➢ Concept of pure and impure substances. ➢ Type of mixtures Learning Outcome Knowledge (Cognitive) Students will know and understand • How to differentiate between pure and impure substances. • The pure substances are elements and compounds. • Differentiate between homogeneous and heterogeneous mixture. • Solvent and solute in solution. • How to express the concentration of solutions. • How to find out the concentrations of solutions in different terms (mass% or volume %). Attitude and values (Affective) Students will value: COMPOUNDS are fixed composition substances. E.g Water, Carbondioxide. SEPARATING DIFFERENT COMPONENTS OF AIR ELEMENTS cannot be broken into simpler substances e.g Oxygen, Nitrogen, TPART 5 PURE SUBSTANCES 5 Q4. What are brass or bronze? The homogeneous solution is a true solution. In the mixture activity conducted just, if we go on adding more and more sugar and go on stirring the solution will go on dissolve the sugar added and clear solution will be obtained till a time will come when no more sugar will dissolve in the solution. Let’s now discuss the terms related to true solution. The Solution is made of solvent (component present in greater amount) and solute (component present in lesser amount in the solution). Depending on the amount of solute present in a given solution it can be dilute or concentrated solution. If in a solution the amount of solute is increased the solution becomes concentrated and on the contrary if the amount of solvent is increased it becomes dilute. Also depending on the amount of solute that can be dissolved in a solution it can be saturated, unsaturated or super-saturated. A Saturated solution contains the maximum amount of solute that can be dissolved in a solution under the condition of temperature and pressure in which the solution exists An unsaturated solution contains less solute than can be dissolved in a saturated solution or in simple words can dissolve more solute under the given temperature and pressure. A super-saturated solution contains more dissolved solute than its saturated solution under the given conditions of temperature and pressure. Concentration of a solutionis the amount (mass or volume) of solute present in a given amount (mass or volume) of solution. The various ways of expressing concentrations are 1. Mass by mass(m/M) percentage of a solution = Mass of solute × 100 Mass of solution 2. Mass by volume (m/V) percentage of a solution = Mass of solute × 100 Volume of solution 3. Volume by volume (v/V) percentage of a solution= volume of solute× 100 Volume of solution Ice - breaker 2 minutes Ice breaker is already included in the above activities Lesson End Written part: The NCERT intext questions Pg15 to be discussed and to be written on their notepad 6 11 minutes The NCERT intext questions Pg18 to be discussed and written From the true solutions the following question to be discussed and written on note pad Pg 28 back ex Q3 3Ans :(a)To produce a saturated solution at313K, 100 g of water needs 62 g of Potassium Nitrate 50 g of water needs 62× 50 i.e 31 g of KNO3 100 (b)From the table, the solubility of KCl at 353K is 54 .At lower temp. the solubility decreases, lets say Room temp. 293K the solubility is 35 , so the difference amount of solute KCl will be separated away as deposit from the solution. (c) at 293K the solubilities of salts are – Potassium nitrate 32 Sodium chloride 36 Potassium chloride 35 Ammonium chloride 37 So, the salt having the highest solubility is Ammonium chloride. (d) The solubility of salt increases with increase in temperature. Pg 18 Intext question Q 3(students to try themselves) 7 NCERT Book Page 29 Ex Qs 7,8 Q3. What is alloy? Give an example Ans: Alloys are mixtures of two or more metals or metal and non- metals and cannot be separated into their components by physical methods. E.g. brass is made of 70%Cu and 30%Zn. Last 2 minutes Value-based information – The sea water is getting all the mud soil and sand particles from river and also millions of years ago during its formation it acquired minerals . Through continuous water cycle occuring it has become salty and much denser than normal water, but it is supporting the marine life and is the route of water transportation serving the whole mankind . That is why we celebrated the World ocean Day on June 8 , 2022. Lesson plan period -2 Learning Objectives ➢ Detail of the heterogeneous mixtures, colloids and suspensions. Learning Outcome Knowledge(Cognitive) Students will know and understand about • The suspensions • The components of a colloid ie. Dispersed phase and dispersion medium. • Different types of sols . 10 Written part 11 minutes Q1 What are the methods to separate heterogeneous mixtures ? Ans: Physical methods like hand picking, Sieving, separating using magnet(if any magnetic substance is present), filtration Pg 18 Intext ques Q2 Q2 How are sol, solution , and suspension different from each other?( Students will write on their own to be guided by teacher) Parameter Solution colloid suspension 1.transparency Transparent i.e. allows light to pass through it Translucent i.e. partially allows the light to pass through. Opaque i.e. does not allow the light to pass through. 2.When passed through a filter paper set in a funnel fixed by a clamp The solution passes as filtrate in a test-tube with no residue on filter paper. The solute particles cannot be separated by filtration in true solution The colloid passes slowly as filtrate in a test-tube with no residue on filter paper. The dispersed phase cannot be separated by filtration in colloid The filtrate obtained in test-tube is clear leaving the other component as residue on filter paper 3.When a strong beam of light is passed through the mixtures and the path of the light is observed perpendicular to the beam The path of light cannot be traced inside the solution The path of light can be traced nicely because of scattering of light by the uniformly distributed particles of dispersed phase . this is called Tyndall effect. The path of light can also be traced in suspension. 4.Stability when the mixtures are allowed to stand for 15- 20 minutes True solutions are stable and remains the same Colloids are also stable Suspensions are unstable and the suspended particles settle down and separate out as sediment. 11 Q3. What is Tyndall effect? A sodium chloride solution does not show Tyndall effect whereas a mixture of water and milk shows it , why? Ans: The scattering of light by colloidal particles is called Tyndall effect. A salt solution cannot show Tyndall effect as the particles are too small (<1nm) in size to scatter light rays falling on them. In contrast the particles in milk solution(a colloidal solution) are big enough(1nm to 100nm) to scatter the rays of light. NCERT BOOK back ex Q 4,5,9. HOTS 6. Smoke and smog both are are aerosols, in which way are the different? 7 MCQ Questions Q1A mixture of Sulphur and Carbondisulphide is (a) Heterogeneous and shows Tyndall effect (b) Homogeneous and shows Tyndall effect (c) Heterogeneous and does not show Tyndall effect (d) Homogeneous and does not show Tyndall effect Q2Tincture of Iodine has antiseptic properties. This solution is made by dissolving (a) Iodine in potassium iodide (b) Iodine in Vaseline (c) Iodine in water (d) Iodine in alcohol Q3 Which of the following are homogeneous in (i) ice (ii) wood (iii) soil (iv) air (a) (i) and (iii) (b) (ii) and (iv) (c) (i) and (iv) (d) (iii) and (iv) Last 2 minutes Importance of food bank, cloth bank and donating toys for the needy people. Lesson plan 12 Period 3 Learning Objectives Detail of the concept separation of components of a mixture. Learning Outcome Knowledge(Cognitive) • Separating the components of a mixture. • Analyze the procedure followed while separating the components from a mixture. • Propose the underlying principle of the following technique o Filtration o Evaporation o Distillation o Fractional distillation Attitude and values (Affective) Students will value: The approach to solution depends on the problem that comes on the way. Analyzing the problem is important which will help to get to the solution. All the techniques that lead to solution are equally important. Psychomotor skills Students develop the qualities like • Understanding the concepts and understand the application • Manipulate and ability to identify the technique of separation to be used for different mixtures. Marzano’s Taxonomy Level 1 Retrieval Recognize the mixture as solution , colloid or suspension. Level 3 Analysis To choose among the separation technique given for mixtures , learn to use the simple technique of Chromatography. Level 4 Knowledge utilization Classifying – organize and identify. Detail of the teaching -learning experiences Lesson beginning (time : 5 minutes) Starting the class with Gayatri mantra. Introduction with a magnet activity (teacher to carry the required things one day prior) The paper is torn into small bits and mixed with iron nail , magnet attracts the nails . Teacher introduces the topic of separation of substances from mixture. Lesson middle ( time : 20 minutes) Different techniques of separation are taught one after another SEPARATION OF COMPONENTS OF A SOLID IN LIQUID MIXTURE (1) Filtration (for suspensions where the solid particles separate by sedimentation) (2) Evaporation (for obtaining non-volatile solute by evaporating volatile solvent). (3) Crystallization (for obtaining crystals of pure solute from its solution). Activity of Filtration and Evaporation to be done in the laboratory (Co-teachers need to inform Harsiddhi ma;am for the conduction of the below experiment. carry the things with them one day prior) 15 Knowledge(Cognitive) • Separating the components of any liquid-liquid solution. • To illustrate a process given in flow-chart Attitude and values (Affective) Students will value: The valuable substances (eg Oxygen ) cannot be obtained very easily, the different components of milk or the diagnosis of blood/urine in laboratory is also application of a separation method called centrifugation. Psychomotor skills Students develop the qualities like • Application of theories that are learnt as concepts. • Comprehending about flow charts Marzano’s Taxonomy Level 1 Retrieval • Recollect the different methods of separation. • Recall the current composition of clean, dry air. Level 2 Comprehension To arrange in proper order from given data. Level 3 Analysis To organize and sort out the necessary steps that are to be followed. Level 4 Knowledge utilization Selection of the best and most cost-effective method when it comes to large scale production Detail of the teaching learning experience 16 Lesson beginning (time : 5 minutes) Starting the class with Gayatri mantra. Introduction of the subtopics to be discussed by oil-water separation activity (co-teachers are to carry the things with them) Things required: a glass (transparent), ½ cup water , ¼ cup oil Activity : Pour the oil and water in the glass and give a swirl , then allow the set-up to stand at rest for a while . Observation: Oil and water separate out in two layers. Learning outcome: you need to be in the light mood to float up and denser thing i.e with heavy and stressful manner you can hardly achieve success. So enjoy what you do. Following portion of the NCERT book content to be referred SEPARATING THE COMPONENTS OF A LIQUID -LIQUID MIXTURE 1. Two immiscible liquids are separated using separating funnel Lesson middle ( time : 20 minutes) Now what if the liquid-liquid mixture is miscible in nature? Subtopic : Separating the components of miscible liquid mixture Introductory activity. To carry nail polish remover and remove nail polish from the nails of girls. Ask them to observe the feeling of coolness. It is due to the volatile substance called acetone. Knowledge utilization : Level 4 a. Distillation to separate a mixture of 2 liquids i. Fractional distillation is used to separate a mixture of two or more miscible liquids for which the difference in boiling point is less than 25K. To separate acetone-water mixture the steps are: 1. The mixture is taken in a distillation flask. A thermometer and a condenser is attached and arrangement of the whole set-up is as shown in figure. 2. The mixture is heated and a close watch is kept on the thermometer. 3. The acetone vopours are condensed in the water-condenser and collected. 4. The water remains in the distillation flask. • The liquid mixture of water and kerosene is poured in a separating funnel. • Let it stand undisturbed for a while when the oil and water separate into 2 layers • The stopcock is opened and the lower layer of water is taken away carefully. • The stopcock is closed as the oil reaches the stopcock 17 Activity of Centrifugation: Teachers heave to take the students to canteen to show the method of centrifugation used in kitchen to prepare Chaas. Centrifugation is the method used to separate substances of different densities from a mixture.This technique is used to separate particles that are very small and they pass through filter paper .The apparatus is called a centrifuge. Colloidal mixtures are separated by centrifugation. The components are separated because the denser particles are forced to the bottom and the lighter ones stay at the top . With the increase in t speed of rotation even the lighter particles can settle down. Learning outcome: you need to be in the light mood to float up and let denser thing i.e with heavy and stressful manner you can hardly achieve success. So enjoy what you do. Centrifugation is used in : • Diagnostic lab in the blood and urine tests. • In diaries to separate butter from cream. • On churning milk the cream gets separated out. Ice breaker (2 minutes) Included in the activities done End of lesson writing part Time : 11 minutes Answer the following questions in your note pad(Not from the back exercises) Q 1. Name the method used to separate the components of air, draw a flow chart for the same. If the gas solution is converted to liquid solution and method of fractional distillation is carried out to evaporate the components of air(the number of components being more than 2 and difference in temp being less than 25 ºC). So, when liquid air (-200ºC) is gradually warmed in a fractional distillation column (say from -196ºC), liquid nitrogen will be first vaporized, followed by Argon and gets separated at different heights of the fractional distillation column and liquid oxygen is collected. The flow diagram is thus A fractionating column is used here as an attachment to the distillation flask which has a condenser to it. The beads in the fractionating column help the vapours to cool and condense repeatedly. The most volatile component separates out first. 20 The process is used to separate sublimable (volatile) component from a non- sublimable impurity. Example of such sublimable solids are ammonium chloride, Capoor, (Camphor) naphthalene and anthracene. Lesson middle ( time : 20 minutes) Sub-topic: ×CHROMATOGRAPHIC SEPARATION× Activity : Beautiful flower making in just 5 minutes. Knowledge utilization : Level 4 ( co-teachers need to carry Butter paper, and blunt black marker, a transparent glass, with water in it.) and students will be informed one day prior in the class to bring the above things along with them. • With the black marker draw a circle and give it a cone shape on the butter paper • Dip the paper in water taken in the such that the line is just above water level/ brush water just below the border of the circle • Watch carefully as water rises up gradually on the filter paper separating the colour components. Observation Colour bands (of different width) are produced on the filter paper along the height up to which the water rose along the length of the paper. Record your own observations. Learning outcome: In your journey in life you will come across different people who will jell with you (like solutions) and they are your true friends with strong bonding (your mind will remain fresh and pure in their company as true solutions). There will be some people who will come in the gesture of a friend just to make your life turbid, it is hard to separate them(just like colloids), so be careful. There are others who doesn’t mix with you , don’t worry just filter them and move ahead. Student will paste their chromatography samples in their notes( by performing the activity at home) Inference This is due to the fact that the ink is a mixture of different colour pigments, the different heights reached by the different pigments depend on the solubility and density of the pigments Questions to clear the concept Q 1.Can you say why is the strip held vertically ? Ans: The effect of gravity on molecules will give better result. Q 2. List 2 uses of chromatography Ans: It is used 1)to identify and separate additives and preservatives added in food items. 2) used in fingerprinting and bio-informatics. Applications : To separate • Colours in a dye. • Pigments from natural colours. • Drugs from blood 21 Ice breaker 2 minutes Included in the activity Lesson end Written part 11 minutes Answer the following questions Pg no. 28 (Back exercises) Q1 Name the technique to be used to separate (i) Butter from curd (ii) Salt from sea water (iii) Camphor from salt (iv) A mixture of kerosene oil , water and salt (v) Small pieces of metal from engine oil (vi) Fine mud particles suspended in water (vii) Wheat grains from husk (viii) Iron pin from sand (ix) Different pigments from extract of flower petal (x) Ammonium chloride from a mixture of common salt and ammonium chloride (xi) Mercury and water mixture Last 2 minutes Talk about food bank , cloth and toy bank Lesson plan 6 Students will know about ➢ Different changes taking place in nature are Physical change and chemical change . ➢ Pure substances (formed of one single type of constituent particle) are elements or compounds. ➢ Element can either be metals, non-metals and metalloids. Learning Outcome Knowledge(Cognitive) • Students will probe into, analyze and identify different changes happening around (natural or manmade). • They will be able to distinguish between element and compounds . • They will further be able to classify elements as metals, non-metals and metalloids. Attitude and values (Affective) Students will value: Everything around them, they will wonder about and appreciate the diversities in natural world of non-living things, how things are categorically and characteristically different from each other and the of their being different. That some changes have no effect on the constituent particles of the substance whereas some changes can give rise to new substance. 22 Marzano’s Taxonomy Details of the teaching-learning experience Details of the teaching-learning experience Lesson beginning (time : 5 minutes) Starting the class with Gayatri mantra. Introduction of the topic with recap questions (Retrieval : level 1) ➢ What do you understand by the word change? ➢ Name some changes that takes places in daily basis in your life? ➢ Identify few changes around you it may be from the class itself? Lesson middle (time : 20 minutes) The changes that take place around us are not all physical in nature but there are some changes where the substances undergoing change cannot be retrieved (burning of fuel) or completely new substance is formed (carbohydrate and oxygen formed from carbon-di-oxide and water vapour during photosynthesis in leaves of plants. Changes in which no new substance is formed , changes take place only in physical properties and states but no change in chemical properties of the substance are called physical changes. Changes which bring about change in chemical composition of a substance and give rise to a new substance with altogether new properties are called chemical changes. Here one substance reacts with another substance and so a chemical change is also called a chemical reaction. Activity time Teachers to carry the things as per activity. Things required: 2 tsp washing powder, 2 tsp turmeric powder, white vingar/lemon(as required), water, a plate , a glass(transparent). Activity 1 Group 1 Group 2 Activity done 1 tsp Washing soda and 1 tsp turmeric powder is mixed dry in a plate. 1 tsp Washing soda and 1 tsp turmeric powder is mixed in a glass and water poured and stirred Colour and texture Non uniform The colour turns orange-red. The colour returns back on adding vinegar Level 1 Retrieval Thinking more about matter already studied in last lesson 1 ‘Matter in our Surroundings’ Level 2 Comprehension To differentiate between physical and chemical change Level 4 knowledge utilization To be able to classify elements as metals, non-metals and metalloids 25 Last 2 minutes Food bank and cloth bank and donating old toys need to be discussed with the students. 26 Sr. No Date Day PW 1 4/7/22 Monday NCERT Exemplar Questions Q1. Answer the following questions (a) Under which category of mixtures will you classify alloys and why? (b) A solution is always a liquid. Comment. (c) Can a solution be heterogeneous? (d) The ‘sea-water’ can be classified as a homogeneous as well as heterogeneous mixture. Comment. Q2. During an experiment the students were asked to prepare a 10% (mass/mass) solution of sugar in water. Ramesh dissolved 10 g of sugar in 100 g of water while Sarika prepared it by dissolving 10 g of sugar in water to make 100 g of the solution. (a) Are the two solutions of the same concentration? (b) Compare the mass % of the two solutions. Q3. Calculate the mass of sodium sulphate required to prepare its 20% (mass per cent) solution in 100 g of water? 2 6/7/22 Wednesday NCERT Exemplar Questions Q4. Answer the following questions (a) Salt can be recovered from its solution by evaporation. Suggest 37% 17% 17% 29% MARZANO TAXONOMY RETRIEVAL COMPREHEND ANALYSIS KNOWLEDGE ANALYSIS 27 some other technique for the same? (b) While diluting a solution of salt in water, a student by mistake added acetone (boiling point 56°C). What technique can be employed to get back the acetone? Justify your choice. (c) Give some examples of Tyndall effect observed in your surroundings? (d) Can we separate alcohol dissolved in water by using a separating funnel? If yes, then describe the procedure. If not, explain. Q5. Explain why particles of a colloidal solution do not settle down when left undisturbed, while in the case of a suspension they do? Q6. Fractional distillation is suitable for separation of miscible liquids with a boiling point difference of about 25 K or less. What part of fractional distillation apparatus makes it efficient and possess an advantage over a simple distillation process. Explain using a diagram. 3 8/7/22 Friday Q7.Give an example each for the mixture having the following characteristics. Suggest a suitable method to separate the components of these mixtures. (a) A volatile and a non-volatile component. (b) Two volatile components with appreciable difference in boiling points. (c) Two immiscible liquids. (d) One of the components changes directly from solid to gaseous state. (e) Two or more coloured constituents soluble in some solvent. Q8. Non-metals are usually poor conductors of heat and electricity. They are non-lustrous, non-sonorous, non-malleable and are coloured. (a) Name a lustrous non-metal. (b) Name a non-metal which exists