Physical Properties of Mixtures, Solutions, and Water



Lesson Synopsis:The physical properties of matter will continue to be investigated in the framework of how substances interact in mixtures and solutions. Students will demonstrate that mixtures can be separated and identify solution as a type of mixture. Students will also use the physical properties of mixtures and solutions to decide whether the properties change or remain the same. TEKS: 5.5Scientific investigation and reasoning. The student knows that matter has measurable physical properties and those properties determine how matter is classified, changed, and used. The student is expected to:5.5CDemonstrate that some mixtures maintain physical properties of their ingredients such as iron filings and sand. Supporting Standard5.5DIdentify changes that can occur in the physical properties of the ingredients of solutions such as dissolving salt in water or adding lemon juice to water. Supporting Standard Scientific Process TEKS:5.1Scientific investigation and reasoning. The student conducts classroom and outdoor investigations following home and school safety procedures and environmentally appropriate and ethical practices. The student is expected to:5.1ADemonstrate safe practices and the use of safety equipment as described in the Texas Safety Standards during classroom and outdoor investigations.5.1BMake informed choices in the conservation, disposal, and recycling of materials.5.2Scientific investigation and reasoning. The student uses scientific methods during laboratory and outdoor investigations. The student is expected to:5.2CCollect information by detailed observations and accurate measuring.5.2DAnalyze and interpret information to construct reasonable explanations from direct (observable) and indirect (inferred) evidence.5.2FCommunicate valid conclusions in both written and verbal forms.5.2GConstruct appropriate simple graphs, tables, maps, and charts using technology, including computers, to organize, examine, and evaluate information.5.4Scientific investigation and reasoning. The student knows how to use a variety of tools and methods to conduct science inquiry. The student is expected to:5.4ACollect, record, and analyze information using tools, including calculators, microscopes, cameras, computers, hand lenses, metric rulers, Celsius thermometers, prisms, mirrors, pan balances, triple beam balances, spring scales, graduated cylinders, beakers, hot plates, meter sticks, magnets, collecting nets, and notebooks; timing devices, including clocks and stopwatches; and materials to support observations of habitats or organisms such as terrariums and aquariums.Getting Ready for InstructionPerformance Indicator(s): Make two mixtures; one must be a solution. Identify whether or not the physical properties of the original substances in each change when the new mixtures are created. Produce a chart that documents changes, if any, in properties. (5.2D, 5.2F, 5.2G; 5.5C, 5.5D) 1C; 5GKey Understandings and Guiding Questions:Las propiedades físicas pueden permanecer igual en algunas mezclas pero pueden cambiar en otras.?Qué propiedades ayudan a separar las diferentes sustancias de una mezcla?Las propiedades físicas de los ingredientes pueden cambiar cuando se combinan en una solución.?Cómo el mezclar afecta la disolución de los ingredientes??Cuáles son las diferencias en los distintos tipos de soluciones?Vocabulary of Instruction:disolversolventesolutosoluciónpropiedadesMaterials:Refer to Notes for Teacher section for materials.Attachments:Handout: Separating Mixtures (1 per student)Teacher Resource: Separating Mixtures KEYHandout: Exploring Solutions Data Sheet (1 per student)Teacher Resource: Exploring Solutions Data Sheet KEY Teacher Resource: PowerPoint: Ways to Separate MixturesHandout: Which MethodTeacher Resource: Which Method KEYTeacher Resource: Evaluate Instructions PI (1 for projection)Resources and References:Suggested Books:Aloian, M. (2008). Mixtures and solutions (Why chemistry matters). NY: Crabtree Publishing Co.Ballard, C. (2009). Mixtures and solutions. Portsmouth, NH: Heinemann-Raintree.Brennan, J. (2011). Mixtures and solutions: The sugar in the tea. Chicago, IL: Norwood House Press Classroom.Karpelenia, J. (2005). Mixtures and solutions. Logan, IA: Perfection learning.Maurer, T. (2012). Mix it up!: Solution or mixture? Vero beach, FL: Rourke Pub. Group.Spilsbury, L. and Spilsbury, R. (2007). Mixtures and Solutions solutions. Portsmouth, NH: Heinemann-Raintree.Advance Preparation: Before the lesson starts, prepare the six bowls of mixtures for each group to use in the Engage activity. Mixture 1: ? cup sand and 1 tablespoon iron filings (sealed in a snack-size, resealable, plastic bag)Mixture 2: ? cup trail mix (may include raisins, almonds, pretzels, and chocolate pieces)Mixture 3: ? cup sand, 1/8 cup cork pieces (2–3 cut into pieces) or wood chips (1/4 cup per class)Mixture 4: ? cup sand and ? cup rocks or pebblesMixture 5: ? cup sand and ? cup waterMixture 6: ? cup salt and 1 teaspoon coarsely ground pepper (sealed in a snack-size, resealable, plastic bag)Prepare attachment(s) as necessary.Background Information:This lesson bundles SEs that address mixtures and solutions in order to set a foundation for understanding and classifying chemical and physical changes.During this lesson, students will classify matter according to their physical properties. Additionally, students will focus on the physical properties of mixtures and solutions and whether those physical properties change or remain the same. In order to truly understand the differences between mixtures and solutions, students will need to be provided with experiences that include the concepts of dissolving and solubility. STAAR Note: Students’ Grade 5 understanding of physical properties of matter will be foundational to the concept of elements and their location on the periodic table in middle school curriculum. Getting Ready for Instruction Supplemental Planning Document Instructors are encouraged to supplement and substitute resources, materials, and activities to differentiate instruction to address the needs of learners. The Exemplar Lessons are one approach to teaching and reaching the Performance Indicators and Specificity in the Instructional Focus Document for this unit. Instructors are encouraged to create original lessons using the Content Creator in the Tools Tab located at the top of the page. All originally authored lessons can be saved in the “My CSCOPE” Tab within the “My Content” area.Instructional ProceduresInstructional ProceduresNotes for TeacherENGAGE – Properties of a MixtureNOTE: 1 Day = 30 minutesSuggested Day 1Say:In the previous lesson, we talked about matter and its physical properties. Ask:What helps us distinguish the physical properties of matter? Answers may vary. Some student responses might be: tools help us measure different observable properties; characteristics help us observe properties; or our five senses can help us observe properties.Divide the class into six groups, and distribute a prepared bowl of mixtures to each group. (see Advance Preparation)Bowl 1: iron filings and sand Bowl 2: trail mixBowl 3: cork and sandBowl 4: rocks and sandBowl 5: sand and waterBowl 6: salt and pepperInstruct the students to make observations regarding the physical properties of each substance and record the contents of each bowl in their science notebooks. Rotate the bowls through each group until all the students have had the opportunity to observe the contents of each of bowl. Ask the following questions for each mixture:Was there more than one substance in each container? (Yes) Can we separate these substances? (Yes)Why are we able to separate the substances? The substances keep their original physical properties in a mixture.In what ways do you think the mixtures can be separated? Answers will vary.What name can we use to describe two or more items that are mixed together, but can still be separated? MixtureAllow students the opportunity to record what they learned in their science notebooks.Materials:bowls (6 per group)trail mix (1/2 cup, see Advance Preparation, per group)iron filings (1 tablespoon, see Advance Preparation, per group)resealable plastic bags (snack- size, see Advance Preparation, 2 per group) sand (1 cup, see Advance Preparation, per group)water (1 cup, see Advance Preparation, per group)rocks or pebbles (1/4 cup, see Advance Preparation, per group)cork (about 1/8 cup, see Advance Preparation, per group)wood chips (1/4 cup, see Advance Preparation, per group) – Optionalsalt (1/4 cup, see Advance Preparation, per group)pepper (coarsely ground, 1 teaspoon, see Advance Preparation, per group)Science Notebooks:Instruct students to list the properties of each of the mixtures in their science notebooks. Creating a chart is one way students could organize the information. Example:BowlContainsProperties12trail mix3cork and sand456EXPLORE – Looking at MixturesSuggested Days 1 (continued), 2, and 3Conduct a demonstration to show that saltwater is a mixture. Set up will include a hot plate, triple beam balance, small pot, about 1/8 cup salt, and water.Put on your safety goggles.Place the small pot on the triple beam balance. Pour in the 1/8 cup salt.Instruct students to draw the investigation set-up in their science notebook. They should include a prediction about the mass of the salt after the water has evaporated.Choose a student to read the mass of the pot and salt. Students should record this number. Place the small pot on the hot plate. Add about ? cup water and stir. Turn on the hot plate.Allow the water to completely evaporate. Remove the pot from the heat source. Place on the hot mitt.Allow the pot to cool. Measure the mass of the pot with the salt again. Choose a student to read this amount. Students should record the amount next to their prediction. The new amount is the “actual amount”. If there is a difference, students should write why the difference has occurred. (Taking the mass after the pot has cooled may need to occur at the conclusion of the Day 2 activity stations.)Safety Note: Watch the evaporation process carefully. When the water evaporates from the pot the salt may “pop”. Students should not be near the hot plate at this time. For Days 2 and 3, students will go through stations where they separate mixtures by various methods.Distribute Handout: Separating Mixtures to each student.Students will be using several different methods to separate mixtures including: physical separation, density, magnetism, filtration, and evaporation.(Optional activity extension) Instruct the students to take a picture of the mixture before and after separation. After the pictures are printed, they can be displayed in the room to reinforce instructional vocabulary.Divide the class into groups of 3–4 students.Remind students of any pertinent safety rules. In addition, when they have finished the investigation at a station, they are expected to restore the station so it is ready for the next group. Students should complete the handout for one station before moving to the next one. Determine how students will rotate through the stations. Instruct students to begin. After students have separated each of the six mixtures and recorded their findings on the Handout Separating Mixtures, facilitate a discussion using the following questions as a guide:Ask:Were you able to separate these mixtures? YesWhat properties helped you to separate the mixture? Answers will vary, but may include shape, attraction to a magnet, etc.What other ways could we have separated this mixture? Answers may include separate by shape, mass, strainer, etc. Listen for student misconceptions about physical separation of matter. Some students may think methods, such as using tweezers to pick out small particles, is a practical method of separation.These substances represent what state(s) of matter? Solid and liquid materials mixed together.Allow time for students to write and illustrate a short summary of their understanding of the concepts learned today.Materials:hot plate (for demonstration, 1 per teacher)safety goggles (for demonstration, 1 per teacher)triple beam balance (for demonstration, 1 per teacher)pot (small, for heating the saltwater mixture, for demonstration, 1 per teacher)gloves or hot mitt (for demonstration, 1 per teacher)containers (such as plastic bowls, 1 per station)magnet (ring or bar, sealed in a snack-size plastic bag, 1 per group)resealable plastic bags (snack-size, for magnets, 1 per group) iron filings (about ? cup, per class)sifter/sieve/strainer (1 per class)filter paper (3 per group)container of water (for pouring, 1 per teacher)beaker (250 mL, 1 per station)sand (1/4 cup, per group)water (1/4 cup, per group)rocks 1/4 cup, per group)cork (2–3 cut into pieces, per group) wood chips (1/4 cup, per group) – Optionalsalt (1/4 cup, per group)pepper (coarsely ground black, 1 teaspoon, per group)camera (digital, 1 per teacher)spoon (plastic, 1 per teacher)Attachments:Handout: Separating Mixtures (1 per student)Teacher Resource: Separating Mixtures KEYSafety Notes: Although students were made aware of safety expectations at the start of the school year, this would be an appropriate time to remind students to: Conduct yourself in a responsible manner at all times while participating in the activity.Follow all written and verbal instructions carefully.?If you do not understand a direction or part of a procedure, ask the teacher before proceeding.? Read all procedures thoroughly.Behave responsibly while conducting the investigation. Horseplay, practical jokes, and pranks are dangerous and prohibited.Dress properly during a laboratory activity. Long hair, dangling jewelry, and loose or baggy clothing are a hazard in the laboratory. Long hair must be tied back.Instructional Notes: Instead of using cork (2–3 cut into pieces), wood chips may be used like on Day 1.Students had the opportunity to learn about ways to separate mixtures in both Grade 3 and 4. They should have had experiences with physical separation, floating/sinking (density), magnetism, filtration, and sifting. Some students may not have seen or experienced evaporation.A word wall could be started in order to have a visual display of the science academic words used in this lesson.Teachers should determine and inform students about pertinent safety procedures and method of rotating through stations.Teachers should also set the expectations of how students should leave the stations for the next group. It is generally expected that a station set-up is prepared for the first group and that each successive group leaves it in the same arrangement.EXPLORE/EXPLAIN – Exploring Solutions as a Special Type of MixtureSuggested Day 4Divide the class into working groups, and distribute the Handout: Exploring Solutions Data Sheet to each student.Instruct students to follow directions at the top of their handout.Distribute the materials for the investigation. Monitor students as they progress through the activity. Ensure that all students have the opportunity to create at least one of the solutions.Determine if washing and recycling the plastic cups is appropriate for your classroom. Discuss the concept of “conservation of resources”. Conservation may include reusing and recycling as opposed to throwing away. Students also need to be aware that washing the cups uses resources (water, soap) and energy (electricity to heat the water).In addition, you will want a container in which each of the different solutions can be disposed.After the students complete the investigation, facilitate a discussion using the following questions as a guide:Ask:What happened to the salt and sugar when they were mixed with the vinegar and water? The salt and sugar appeared to ‘disappear’ because it dissolved and mixed evenly with the liquids.What seemed to ‘disappear’ in these mixtures? The solid substanceDo you think that the substances are still there? Answers may vary. How are mixtures and solutions different? The substances in a mixture retain their physical properties, which make them easy to separate. In solutions, the substances lose some of their physical properties. Solutions are more difficult to separate.Why did you need to stir the substances? Stirring helped the salt and sugar dissolve faster. When molecules move faster, they have more energy and are able to interact more quickly with other substances.Remind students of the activity they did during the Engage Section. Mixtures are two or more substances, mixed together, that can be easily separated. Ask:What are some combinations that mixtures could have? Mixtures can be any combination of liquids, solids, and gases.What proportions can be found in mixtures? Mixtures may contain any proportion of the components from which it is made.How would you describe air? Air is a mixture of gases. How would you describe a solution? A mixture of a solid, liquid, or gas dissolved in another liquid is called a solution.What is one way a solution appears different from a mixture? The solid seems to disappear, but it is distributed throughout the mixture. Ask:What are some of the unique properties that make these mixtures solutions? Answers may vary, but should include: the solids dissolve but are still there and can be separated; the properties of the substances remain unchanged; can be dissolved in other liquids besides water; etc.Why are these solutions still considered mixtures? Two or more substances are being mixed together.In these solutions, what substance was being dissolved? The solid or the salt and sugarWhat substance was doing the dissolving? The liquidWhat substance is the solvent? The liquid (water or vingegar).After the questions (above) have all been discussed, allow students the opportunity to correct anything from their work and write a description in their science notebook of what makes mixtures and solutions different.To summarize the activity,Say:During the activity, “Separating Mixtures”, you discovered that a mixture is a combination of two or more substances that keep their original physical properties.You explored a special type of mixture called a solution. In a solution, one substance dissolves and mixes evenly throughout the mixture.Solutions are more difficult to separate than mixture because the combined substances are distributed evenly. The components do not all retain their original physical properties.Materials:cups (clear, plastic, 6–8 ounce, 5 per group)spoons (plastic, 5 per group)water (per class)salt (2 g, per group)sugar (1 g, per group)pancake syrup (5 mL, per group)lemon juice (5 mL, per group)vinegar (100 mL, per group)balance (1 per group)graduated cylinder (50 mL or 100 mL, 1 per group)Attachments:Handout: Exploring Solutions Data SheetTeacher Resource: Exploring Solutions Data Sheet KEYInstructional Notes: To manage the large quantity of materials for this investigation, consider placing all materials for one group on a tray or in one area. A materials manager could be appointed in each group to retrieve and return materials.Determine if washing and recycling the plastic cups is appropriate for your classroom. In addition, you will want a container in which each of the different solutions can be disposed.If students are having difficulty grasping the concept that the sugar or salt is still in the water even though it looks as though it has “disappeared”, you could use the analogy of an “Hide and Go Seek”. People are there, you just can’t see them. The solid is hiding in the liquid. Students should work with their group to create a definition for the word mixture and the word solution.-1905127000Science Notebooks:When students are writing in their science notebooks consider using the “Line of Learning” strategy. More information can be found at: sheets should be affixed in student science notebook. EXPLAIN – Exploring SolutionsSuggested Day 5Using the Handout: Exploring Solutions Data Sheet, facilitate a guided discussion about the results. How does mixing affect the dissolving of ingredients? Answers will vary depending on the ingredients.How do various types of solutions differ? Answers will vary depending on the ingredients.In the course of discussion, be mindful that it is critical that students recognize the properties that make up a solution. Allow students time to brainstorm with their classmates in order to compare and contrast mixtures and solutions. Instruct students to create a graphic organizer in which they can record data in their science notebooks. Students should have the opportunity to share their thinking with their classmates. Encourage students to add examples to their graphic organizer.Attachments:Handout: Exploring Solutions Data Sheet (from previous activity)ELABORATE – Ways of Separating MixturesSuggested Day 6Show the PowerPoint: Ways to Separate Mixtures.Distribute the Handout: Which Method. Have students complete the handout.After students have completed the handout, facilitate a discussion to review the answers using the Teacher Resource: Which Method KEY as a guide.Attachments:Teacher Resource: PowerPoint: Ways to Separate MixturesHandout: Which Method (1 per students)Teacher Resource: Which Method KEYCheck for Understanding:As students are completing the Handout: Which Method, the teacher could monitor student work and at the same time, informally assess student understanding. EVALUATE – Performance indicatorSuggested Days 7 and 8Performance IndicatorMake two mixtures; one must be a solution. Identify whether or not the physical properties of the original substances in each change when the new mixtures are created. Produce a chart that documents changes, if any, in properties. (5.2D, 5.2F, 5.2G; 5.5C, 5.5D) 1C; 5GRefer to the Teacher Resource: Evaluate Instructions PI for information on administering the performance assessment.Materials:lesson materials (such as sand, salt, water, vinegar, salt sugar, per class)lesson tools (such as magnet, hand lens, hot plate, beakers, funnel, filter paper, per class)paper (either plain or construction, 1 sheet per student)markers or colored pencils (per group)Attachments:Teacher Resource: Evaluate Instructions PI (1 for projection)Safety Notes:If a group choses to use a hot plate in order to evaporate a mixture, then each student in the group should be wearing safety goggles.Review safety procedures for this activity.No tasting of the liquid allowed. ................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download