Science 3

3. ____________________ 4. __________________5. ____________________ 6. ___________________7. _____________________ 8. __________________9. ______________________ 10._______________________ Key to answers on page 28. Let’s SummarizeA. LABORATORY APPARATUS AND EQUIPMENT1. Beaker – a deep, wide-mouthed, thin-walled cylindrical vessel with a pouring lip used to measure large quantities of liquid; can also be used to store or contain liquid mixtures2. Volumetric Flask – a vessel used to contain large amounts of liquid; can also be used to measure volume of volatile liquids3. Florence Flask – a round, flat-bottomed, long necked vessel used to measure large quantities of liquid and to hold boiling liquids4. Erlenmeyer Flask – a cone-shaped vessel with a narrow flat bottom used to measure large amounts of liquid; also serves as receiver or stores liquid that has undergone titration that is to be kept for further analysis5. Reagent Bottles – a vessel used to contain chemicals that are mixed or added with other substances to bring about chemical reactions to form new substances or compounds. - 20 -

6. Test Tubes – small glass-tube shaped containers that are closed and round at the bottom with open end used to mix, heat and store small amount of liquids and substances.7. Graduated Cylinder – a narrow cylindrical vessel used to measure volume of liquids and volume of irregular solids by water displacement8. Volumetric Flask – can be used to measure the volume of volatile liquids9. Erlenmeyer Flask – a cone-shaped vessel with a narrow flat bottom used to measure large amounts of liquid10. Pipette – used to transfer small amounts of liquid of known volume to another container11. Burette – a glass tube with measurements marked on the side and a stopcock at the bottom, used to accurately measure the volume of liquid before releasing it in another container.12. Medicine Dropper – a small glass or plastic tube with rubber bulb at one end that is used to suck up liquid and release it to another container one drop at a time13. Iron Stand – supports the iron ring and iron clamp during heating, distillation and other extraction purposes14. Iron Ring – used as base to hold the wire gauze and any other container to be heated15. Iron Clamp – used to hold the test tube, distilling flask, and other apparatus to be heated16. Crucible Tong – a tool used to hold hot materials or apparatus17. Crucible and cover – a heat resistant container with cover in which ores or materials are melted18. Evaporating Dish – a shallow heat resistant porcelain dish in which a solution is heated and allowed to evaporate leaving a residue on its plate19. Watch Glass – a shallow, round crystal or glass dish used to hold small amounts of substances to be tested for a reaction20. Mortar and Pestle – a pair consisting of a strong vessel and a club-shaped implement used to pound or grind solid substances into powder or granule forms21. Triple Beam Balance – used to measure the mass of an object22. Test Tube Brush – a slender and long brush with long handle used to clean test tubes23. Thermometer – used to measure the hotness and coldness of an object24. Funnel – a cone-shaped tool with large opening at the top and a small opening or tube at the bottom used to guide liquids and other substances through a small opening; used to hold filter paper during filtrationB. LABORATORY PRECAUTIONS1. Inside the Laboratory: a. Do not eat food, drink beverages, or chew gum in the laboratory. Do not use laboratory glassware as containers for food or beverages. b. Wear safety goggles and aprons c. Always keep the working area clean and orderly. d. Know the locations and operating procedures of all safety equipment. e. Notify the instructor immediately of any unsafe conditions you observe. - 21 -

2. Handling Chemicals a. All chemicals in the laboratory are to be considered dangerous. Do not touch, taste, or smell any chemical unless specifically instructed to do so. b. Check the label on chemical bottles twice before removing any of the contents. c. Never return unused chemicals to their original containers. d. Acids must be handled with extreme care. ALWAYS ADD ACID SLOWLY TO WATER. e. Handle flammable hazardous liquids over a pan to contain spills. Never dispense flammable liquids anywhere near an open flame or source of heat.3. Handling Glassware and Equipment a. Always lubricate glassware (tubing, thistle tubes, thermometers, etc.) before attempting to insert it in a stopper. b. When removing an electrical plug from its socket, grasp the plug, not the electrical cord. Keep your hands dry when working with electricity. c. Do not immerse hot glassware in cold water; it may shatter. d. Report damaged electrical equipment immediately.4. Heating Substances a. TURN OFF THE GAS AT THE GAS OUTLET VALVE after using. b. Never leave a lit burner unattended. Never leave anything that is being heated or is visibly reacting unattended. c. Use tongs or heat-protective gloves when holding or touching heated apparatus.C. WARNING SIGNSSAFETY SYMBOLS HAZARDDISPOSAL Special disposal considerations requiredBIOLOGICAL Organisms or organic materials that can harm humansEXTREME HEAT Objects that can burn skin by being too cold or too hot - 22 -

SAFETY SYMBOLS HAZARDSHARP OBJECT Use of tools or glassware FUME that can easily puncture or ELECTRICAL slice skin CORROSIVE Potential danger to olfactory TOXIC tract from fumes RADIOACTIVE Possible danger from electrical shock or burn Substances (acids and bases) that can react with and destroy tissue and other materials Poisonous substances that can be acquired through skin absorption, inhalation, or ingestion Radioactive substances such as uranium and plutoniumPosttestMultiple Choice: Choose the letter of the best answer. Write the chosen letter on aseparate sheet of paper.1. When doing an experiment like heating or anything that uses fire, what should you beready with?a. an apron c. a pail of waterb. a damp cloth d. a wet tissue paper2. Acids must be handled with extreme care. In diluting an acid, what should you do?a. Do it in any way you want. c. Always add the water to the acid.b. Always add acid slowly to water d. Mix the acid to the water by stirring - 23 -

3. Given three laboratory apparatus: spring balance, graduated cylinder and test tube.Which will you use to get the mass of water?a. the spring balance c. the test tubeb. the graduated cylinder d. all of the above4. Which does NOT belong to the group? c. wire gauze a. graduated cylinder d. Florence flask b. beaker5. You have come across this icon pasted on a bottle. What does this mean? a. It is a metal c. It is a nonmetal b. It is radioactive d. It is poisonous/toxic6. While inside the hospital’s laboratory area, you saw this icon in one of the rooms. What does this mean? a. The room is strictly for nurses. b. The room is only for technician. c. The room is used for X-ray purposes. d. The room is used for storage of hazardous chemicals.7. While reading the procedure of an activity, you happen to come across this icon. What does it mean? a. Always wash your hands after an experiment. b. “CLOSE THE FAUCET AFTER USE.” c. Always use water in all experiments. d. Water is a universal solvent.8. Given three laboratory apparatus: beaker, test tube and test tube brush. Which will youuse to perform titration?a. beaker c. evaporating diskb. burette d. pipette9. In an experiment you are asked to get the mass of a piece of stone. What apparatus willyou use?a. erlenmeyer flask c. graduated cylinderb. florence flask d. triple beam balance10. You have come across this icon. What does this mean? a. It is poisonous/hazardous. c. It is a nonmetal. b. It is radioactive. d. It is a metal.11. Which of the following is NOT in the group of apparatus that are used for heating?a. alcohol burner c. crucibleb. beaker d. watch glass - 24 -

12. Which of these apparatus will you use if you want to measure the density of a certain liquid? a. beaker and test tube b. test tube and platform balance c. beaker and graduated cylinder d. graduated cylinder and triple beam balance13. What will you use to transfer a liquid into a small-mouthed bottle without spilling?a. a funnel c. a test tubeb. a petri dish d. a graduated cylinder14. When doing an experiment like heating, and a Bunsen burner is not available, what willyou use as replacement for the Bunsen burner?a. a candle c. an alcohol lampb. a gas stove d. a long and thick thread15. Which of the following apparatus does NOT belong to the group? a. b. c. d.16. One of the most important safety rules is to: a. avoid heating objects. b. read the procedure of the activity. c. follow your classmates’ directions. d. follow the instructions carefully as advised17. Why is wire gauze necessary when heating?a. Avoid breakage. c. To make heating fasterb. Avoid direct contact. d. To make the set-up look attractive.18. Which of the following apparatus does not measure mass?a. balance beam c. Newton scale balanceb. double beam balance d. triple beam balance19. Which of the following symbols suggests that you are working with flammable substances in a laboratory? a. b. c. d.20. All of the following laboratory instructions are correct EXCEPT: a. Always add acid slowly to water. b. Always wear your lab gown or apron. c. Start the experiment without being told. d. Taste substances in the laboratory room when you are not told to do so. - 25 -

II. Label the parts of the triple beam balance: 12 3 45III. Name the apparatus below:34 5 6 71 82 9 10 7 Key to answers on page 28. - 26 -

Key to AnswersPretestI. 6. a 11. b 16. b1. c 7. c 12. d 17. d2. d 8. b 13. c 18. b3. c 9. a 14. d 19. b4. d 10. c 15. a 20. b5. aLesson 1Self-Test 1.11. F 6. G 11. H2. E 7. A 12. L3. O 8. B 13. I4. C 9. K 14. N5. D 10. J 15. MSelf-Test 1.21. left pan2. the sum of the readings on the three beams3. adjustment knob4. beams5. right panLesson 2Self-Test 2.11. NO 6. YES2. YES 7. NO3. YES 8. NO4. NO 9. YES5. NO 10.YES - 27 -

Lesson 3Self-Test 3.11. ELECTRICAL 6. CORROSIVE2. DISPOSAL 7. HYGIENE3. TOXIC 8. SHARP OBJECT4. RADIOACTIVE 9. EXTREME HEAT5. FLAMMABLE 10. FUMEPosttestI. 6. c 11. d 16. d1. b 7. a 12. d 17. b2. b 8. c 13. a 18. a3. d 9. d 14. c 19. b4. c 10. a 15. b 20. c5. dII. III. 6. Erlenmeyer flask1. pan 1. iron ring 7. burner2. poise(s) 2. iron stand 8. medicine dropper3. beam(s) 3. wire gauze 9. watch glass4. pointer 4. test tube 10. test tube holder5. adjustment knob 5. beakerReferencesHagad, R.H. (2003). Chemistry. Quezon City, Philippines: ALCO Printers.Lemay, E.H & Beall, H. (2002). Chemistry in the changing world. Glenview, USA: Prentice Hall.Mendoza, E. & Religioso, T, (2001). Chemistry. Quezon City, Philippines: SIBS Publishing.Nueva España, R.C. & Apostol, J, (2004), Chemistry. Quezon City, Philippines: Abiva Publishing.Oxtoby, D.W. & Freeman, W.A. (1998). Chemistry: The science of change. CA: Saunders College Publishing. - 28 -

Module 3 Classifying Matter as Pure Substances What this module is about Have you been to SM super mall, Robinson’s department store, Walter Mart’sfurniture shop, or any mall near your area? Do you know that going to the mall is very muchlike going to the market? People go to market (or to the mall) to buy stuff like chicken, fish,meat, eggs, vegetables, noodles, clothes, shampoo, oil, vinegar, puto, detergent and manyother things that are basic to our everyday life. In science, these numerous things around usthat we see, use and even eat are referred to as matter. Do you want to know more aboutmatter? This module is designed to guide you in defining matter and in classifying differentsamples of matter as pure substances. It also intends to assist you in grouping puresubstances into elements and compounds. So, have fun while reading and learning thefollowing lessons:  Lesson 1 – Defining Matter  Lesson 2 – Classifying Matter  Lesson 3 – Pure Substances: Elements or Compounds? What you are expected to learn After going through this module, you should be able to: 1. define matter; 2. give examples and non-examples of matter; 3. identify the characteristics of pure substances that make them different from other kinds of matter; 4. differentiate elements from compounds; 5. classify the element as a metal, nonmetal or metalloid based on observable characteristics; and 6. distinguish acids from bases using common indicators.

How to learn from this moduleTo learn most from this module, here are some tips that you have to remember.1. Before proceeding to the lessons, don’t forget to take the pretest. Your score in the test will give you an idea how much time you need to devote to each lesson.2. Read the instructions and bear in mind precautionary measures.3. Make sure that the needed materials are already prepared before doing any of the activities.4. Always answer the Self-Test and compare your answers to the key to correction.5. For you to know how much you have learned from the module, answer the post- test! Enjoy reading!What to do before (Pretest)Multiple Choice. Choose the letter of the best answer. Write the chosen letter on aseparate sheet of paper.1. Which of the following best describes matter?a. It has weight. c. It is a form of energy.b. It occupies space. d. It has a definite shape.2. Which is a non-example of matter? c. light a. fire d. human heart b. clay3. Which statement is TRUE regarding pure substances? a. Pure substances maybe homogeneous or heterogeneous. b. Pure substances have definite boiling and melting points. c. Pure substances are physical combinations of two or more elements. d. Pure substances can be further broken down into simpler substances.4. At sea level, an odorless and colorless Liquid A boils at 100˚C and melts at 0˚C. Whatinference can be drawn from this observation?a. Liquid A is a metal. c. Liquid A is a nonmetal.b. Liquid A is a mixture. d. Liquid A is a pure substance. -2-

5. Which of the following are pure substances?1. tin 2. brass 3. fog 4. limea. 1 and 2 c. 1 and 4b. 1 and 3 d. 2 and 36. Which of the following statements is true for both elements and compounds? a. They are homogeneous. b. They are the simplest form of matter. c. They are commonly found free in nature. d. They can be broken down into simpler substances.7. Copper, aluminum and gold are metals. Which incorrectly describes a metal?a. Metals are ductile. c. Metals are good insulators.b. Metals are malleable. d. Metals are good conductors of heat.8. Sulfur, carbon and the noble gases are nonmetals. Which of the following bestdistinguishes a nonmetal from a metal?a. Its homogeneity. c. Its brittleness.b. Its boiling point. d. Its ductility.9. All of the following will change blue litmus paper to red excepta. vinegar c. Sprite or Seven-upb. kalamansi juice d. detergent solution10. Your chemistry teacher asked you to test Substance Y using a litmus paper. You havenoted that the red litmus paper turned to blue. This observation indicates that thesubstance isa. metallic c. acidicb. neutral d. basic Key to answers on page 18.Lesson 1. Defining Matter Do you know that chairs, plates, air, wood, water, mud, sea and birds have one thingin common? They are all classified as matter! So, what is matter? Can we say that all thethings around us are examples of matter? To answer these questions, let us performActivity 1.1. -3-

Figure 1.1 Varied examples of matter What you will do Activity 1.1Materials Needed: scratch papers, pencil/ball pen glass, water, 2 small stonesProcedure: 1. Proceed to your kitchen and take a closer look at the objects/things that you see. On your paper, write five of the items that you see in the kitchen. 2. Go to the bathroom and then again list 5 items that you find there. 3. This time, go to your backyard. List 5 more items that you can find in the area. 4. At this point, there should be a total of 15 items in your list. Now, go over your list and try to identify which is the heaviest among the objects. Identify also which is the lightest. 5. Then, rank the objects 1-15. Rank 1 will be for the lightest object while rank 15 will be for the heaviest. 6. Half-fill a glass with water. Then, put some stones in it. Observe what will happen to the water level as stones are added into the glass. Have you done Activity 1.1? If yes, then let us analyze your observations. What items have you included in your list? In your kitchen, did you notice the tablesalt, oil, vinegar, table, chair, plate, glass, frying pan, spoon and fork? What about insideyour bathroom, did you include soap, detergent, towel, pail, shampoo or water in your list?And when you went to your backyard, what did you see? Are you not amazed of thenumerous things that are around us? Now, when you ranked the 15 items from the lightestto the heaviest, what generalization have you thought of? Right! The things that you havelisted have mass! It may either be light or heavy! Can we say that all the objects listedabove have mass, too? Yes, all of them have mass. In Procedure 6, did you notice that the water level rose when 2 small stones wereadded? Why? The water level rose because just like water, the stones occupied space. -4-

And since the space being occupied by water cannot be occupied by the two stones at thesame time, the water level had to rise. To explain this further, let us use an analogy. If youare seated in a bus with two of your friends, can another friend of yours seat on where youare seated? Of course not! For your friend to sit on that same spot where you are seatedyou have to stand and let your friend occupy the space. In the same way, the water levelrose to give way to the stones that were placed in the glass. The amount of water displacedwas the space occupied by the two small stones. Thus, water and stones occupy space. Inscience, space occupied is referred to as volume. In Procedures 1, 2 and 3, you have discovered that there are a lot of things aroundus. In Procedure 4 and 5, you have learned that these objects around us have mass. Theyare either light or heavy. In Procedure 6, you have shown that objects occupy space or theyhave volume. Now, how do we call the objects or things around us that have mass andoccupy space? In science, these things are called matter! So, is radio an example of matter? Yes, it is! How about the sound coming out of theradio, is it matter? Let us see……Does sound occupy space? No, it doesn’t! Is soundheavy or light? No, it isn’t! Therefore, is sound an example of matter? No, it is not. Sound,as you have learned in Science 1, is a form of energy! What you will do Self-Test 1.11. Which of the following are non-examples of matter? a. air b. water c. light d. fire e. heat2. Name at least 10 examples of matter. Key to answers on page 18.Remember! Matter is anything that has mass and occupies space.-5-

Lesson 2. Classifying Matter Chemistry is one of the branches of physical sciences that deals with the study ofmatter and its changes. Thus, the numerous kinds of matter around us are the same thingsthat chemists study. Due to the enormous variety of matter, chemists realized the need togroup them together so that it would be easier to study them as groups rather than asindividuals. How can we group samples of matter together? To give you an idea on howenormous examples of matter are classified, let us do Activity 2.1! What you will do Activity 2.1 If your family owns a sari-sari store, how will you arrange the following items in yourstore? How did you group the items in your store? Let us check if your groupings are thesame as mine. Vinegar, soy sauce and fish sauce are all condiments so all will be put in thesame location. Chocolate drinks, orange juice and soft drinks should be grouped togetherwhereas wafer and loaf bread should form another group. And of course, bubble gums andcandies will form another group. Now, what was your basis in grouping the materials above? Right! The materialsabove are grouped together based on their characteristics. Similarly, different samples ofmatter can be grouped together or classified based on properties that they share. Matter can be classified based on its composition. On the next page is a schematicdiagram showing this classification: Based on the diagram, the major groupings of matter are pure substances and -6-

mixtures. Copper, water, table sugar, and salt are examples of pure substances while saltsolution, sugar solution, mayonnaise and halo-halo are examples of mixtures. Sincemixture is best defined as the physical combination of two or more pure substances invarying proportions then to understand mixtures, we must first have a clear understanding ofpure substances. Thus, this module will be focusing on pure substances. In Module 3, youwill be learning more about mixtures. It is therefore advised that you study this moduleintently before going to Module 3. As seen in the diagram, pure substances are homogeneous. What do we meanwhen we say that a substance is homogeneous? Let us take a closer look at the differentsamples of pure substances right at your very house. MATTER Pure Substance Mixture Homogeneous Element Suspension Colloid Solution Heterogeneous HomogeneousMetal Metalloid Nonmetal Compound Inorganic Organic Acid Base Neutral Figure 2.1 Classification of Matter -7-

What you will doActivity 2.2Materials Needed: glass plate pinch of sugar pair of scissors water pinch of salt copper wireProcedure:1. Examine carefully each of the following: water in a glass, sugar and salt on a plate and the copper wire. Identify the number of phases in each of these pure substances: ______________________________________________________________________________ ______________________________________________________________________________\2. Drink the water. How does it taste? _________________________________________3. If you’ll be getting another glass of water from the faucet, will it taste the same as the water in the first glass? ___________________________________________________4. Taste the pinch of salt. How does it taste? Do you expect the taste of salt to be always the same? _____________________________________________________________5. Taste the pinch of sugar. How does it taste? Do you expect the taste of sugar to be always the same? _______________________________________________________6. Get a piece of copper wire. Cut it into pieces. Compare the pieces of copper wires, what do you notice? ______________________________________________________ Have you noticed that sugar is composed of only one phase of matter? In the sameway that salt, copper wire and water are all composed of just one phase. The activity showsthat the characteristics of the pure substances are the same throughout its samples. Thismeans that potable water is always colorless, tasteless and odorless. Sugar is always sweetwhile salt is always salty. Likewise, the properties of the pieces of copper wire are just thesame as the properties of the original wire. What does this imply? It implies that all puresubstances are homogeneous. When we say homogeneous, we are speaking of a onephase system whose properties are the same the whole time. Why are all pure substances homogeneous? All pure substances are homogeneousbecause they are made up of only one kind of matter. In addition, the characteristics ofdifferent samples of a pure substance are the same because all pure substances have adefinite composition. For instance, the water in America will have the same characteristicsas the water in the Philippines. Why is this so? This is because water, in any part of theworld, is always made up of water molecules, having two hydrogen (H) atoms and oneoxygen (O) atom. Ooops! The word atom and molecule maybe new to you, but don’tpanic! You will learn more about atoms and molecules as we progress with our discussion -8-

of chemistry. For the time being, what I want you to understand is the definite compositionof pure substances. Let us then have an analogy to let you better understand thischaracteristic of pure substances. We know that a family is always composed of a father, amother and their children (or child). In the same way that a water molecule will always bemade up of two atoms of hydrogen and an atom of oxygen. If we only have one atom ofhydrogen and one atom of oxygen, will it give us a water molecule? You are right! Sincethe composition of water is fixed then to have water there should be two atoms of hydrogenand an atom of oxygen in its molecule. On the other hand, copper is also a pure substancebut it is only made up of copper atoms. But just the same, like water, its composition isfixed!Other Distinguishing Characteristics of Pure Substances What other distinguishing characteristics of pure substances will help us betterdifferentiate them from mixtures. To find out, let us perform Activity 2.3.What you will doActivity 2.3Materials Needed: casserole, water, thermometer, glassProcedure:1. Fill a glass with water. Then, transfer the water into a casserole. The2. When the water is already boiling, get the temperature of the water. temperature is the water’s boiling point.3. Repeat Steps 1-3, but this time boil two glasses of water.Caution: Be careful when heating! Do not leave the casserole while you are boiling water. When you are through make sure that the source of heat is put off.Use a laboratory thermometer. You may borrow one from school. Be extracareful if you would be using a thermometer with mercury. If you accidentallybreak it, do not touch the silvery substance (that’s mercury!). Mercury ishazardous to your health. What have you discovered in the activity? Is the boiling point of one glass of waterthe same as the boiling point of two glasses of water? Yes, you are right! The boiling pointof water is constant. If you will boil water at sea level, its boiling point is 100ºC, in the sameway that the melting point and freezing point of water is always at 0ºC! Unlike mixtures, the boiling points and melting points of pure substances are definite! -9-

What you will do Self-Test 2.1Which of the following samples of matter will you classify as a pure substance? 1. Sample A is a colorless and odorless liquid that boils at 100ºC. 2. Sample B is made up of two liquids. One of the liquids is colorless while the other is yellowish. 3. Sample C is composed of a white solid that dissolves in water. When Sample C is heated, its boiling point ranges from 100ºC to 110 ºC. Key to answers on page 18. Remember!  Pure substances are always homogeneous.  Pure substances are made up of only one kind of matter.  Pure substances have definite composition.  Pure substances have definite melting and boiling points.Lesson 3. Pure Substances: Elements or Compounds As earlier mentioned, copper and water are both pure substances. But why is it thatcopper is made up of copper atoms only whereas water is made up of molecules, and eachmolecule of water is composed of one atom of oxygen and two atoms of hydrogen? This isbecause pure substances can be further classified as compounds and elements. Copper isan example of an element while water is an example of a compound. Notice that water ismade up of elements, hydrogen and oxygen. Thus, before we study compounds, let us firsttake a closer look at the pure substances that make up a compound ---- the elements!All about Elements Elements are said to be the building blocks of matter. It cannot be broken down intosimpler substances simply because it is the simplest form of matter. To date, there areabout 116 elements. Most of these elements are naturally occurring and only a smallpercentage of elements are man-made. But with the advent of new technology, more andmore elements are being synthesized inside the laboratory. The periodic table of elements gives us various information regarding the simplest - 10 -

form of matter. The elements in the table are arranged according to increasing atomicnumber. Examine the periodic table below. Did you notice the lines that look like a ladder? The ladder helps us to distinguish the location of the metals and nonmetals in theperiodic table. Metals, nonmetals and metalloids are classifications of elements.Remember that the elements to the right of the ladder are nonmetals whereas those to theleft are metals. This will give you an idea that 75% of the elements are metals. On theother hand, the metalloids or semi-metals are those in the ladder. Did you notice as well that the elements are being represented by chemical symbols?Hydrogen is symbolized by capital letter H, helium with He, carbon with C, boron with B andcalcium with Ca. H, He, C, B, and Ca are what we refer to as chemical symbols. Can youidentify the chemical symbols of the most common elements? - 11 -

What you will doSelf-Test 3.1A. Using the periodic table of elements, identify the symbols of the following:1. Iron 2. Copper 3. Sodium 4. Magnesium 5. GoldB. Based on the location of the element in the periodic table, identify if the element in A is a metal, a nonmetal or a metalloid. Key to answers on page 18. Now, how do we distinguish a metal from a nonmetal? Activity 3.1 will give you anidea on how these two can be differentiated. What you will do Activity 3.1Materials Needed: iron nails charcoal ( 2 chunks will do) hammer magnetProcedure:1. Examine closely an iron nail and a chunk of charcoal. What differences can you notice? ______________________________________________________________________ ______________________________________________________________________2. Hammer the iron nail and do the same to the chunks of charcoal. What did you notice? ______________________________________________________________________ ______________________________________________________________________3. Determine which will be attracted by a magnet- the charcoal or the iron nail.__________ Based on Activity 3.1, what are the characteristics of metals? What about thenonmetals? Let us see…..In Procedure 1, did you notice that unlike nonmetals, the metals areshiny? They are lustrous (or they possess luster)! Procedure 2 shows that metals are hard while nonmetals are brittle. The charcoaleasily breaks. On the other hand, you can actually hammer metals into sheets without - 12 -

breaking. This characteristic of metal is known as malleability. Aside from this, metalsexhibit ductility, which is the ability to be drawn into wire. Procedure 3 showed that metals are attracted to a magnet while nonmetals are not. Another characteristic of metals is its ability to conduct heat and electricity. As aproof, look at your frying pan; it is made of metal. Inside the black cable that is responsiblefor the conduction of electricity is copper, which is also a metal! On the other hand,nonmetals are good insulators since they are not good conductors of heat and electricity. What about the metalloids? The metalloids have the characteristics of metals andnonmetals. If the position of the metalloid in the periodic table is nearer the nonmetal, thenit has more nonmetallic characteristics compared to its metallic properties and vice versa.Element + Element = Compound? Does the combination of an element plus an element always result to a compound?No, it doesn’t! Why? If two metals are just physically combined, it will result to theformation of an alloy. Alloy is not a compound; it is just a mixture because it is just aphysical combination of two pure substances, in this case - elements. So, how then do wedescribe a compound? A compound is a combination of elements. This is right! Butremember that a compound is a chemical combination of two or more elements. A chemicalcombination results to a formation of a new substance. What does this mean? Toelaborate, let us take sodium chloride (NaCl) or table salt as our example. Table salt is made up of two elements namely: sodium and chlorine. Sodium is avery reactive metal. Once you have placed even a pea-size of this metal in water, a violentreaction occurs! On the other hand, chlorine exists as chlorine gas, which is used as awarfare gas during the war. This implies that it is as well a “not-so-friendly” substance. Butwhen a chemical combination transpires between the two, it would result to the formation ofa new substance. And this new substance has a new set of characteristics that are quitedifferent from the characteristics of the elements comprising it…..Can you name somecharacteristics of table salt that are the same as the properties of the elements comprisingit? Does salt violently react with water? Is it toxic? Of course, if taken in excess, it wouldas well be bad for the health. But, table salt is part of our everyday life since we always useit as a seasoning. Now, how do we separate the components of compound? For instance, can weseparate the components of water by just boiling it? Let us try. What you will do Activity 3.2Materials Needed: casserole, water - 13 -

Procedure:1. Put some water in a casserole.2. Let the water boil. When it is already boiling, observe what happens. ______________________________________________________________________ ______________________________________________________________________ Were you able to separate the water into its components – hydrogen gas and oxygengas? No, you were not able to do so! The water simply evaporated. It just changed itsphase from liquid to gas but the gaseous substance was still water! What does this imply?This implies that physical processes cannot be used to separate the components of water.Since water is a chemical combination of elements in a definite proportion by mass, then toseparate its components, a chemical process has to be employed. Electrolysis, which makes use of direct electric current, is being used to separate thecomponents of both sodium chloride and water. Remember that compounds can only be formed if the right amounts of itscomponents are present. Compounds are only formed when elements are present in adefinite proportion by mass! What you will do Self-Test 3.2Which of the following can be classified as a compound? 1. carbon dioxide 2. ice 3. salt solution 4. wine 5. lime ( apog) Key to answers on page 18.Acidic or Basic? Compounds may be further classified as an acid, base or neutral. The easiest way todistinguish these three is through the use of indicators. The most common indicator in theclassroom is litmus paper. How do we distinguish acids from bases using a litmus paper? - 14 -

Let us then perform Activity 3.3? What you will do Activity 3.3Materials Needed: Detergent solution Apog in water Kalamansi juice Seven-up or SpriteProcedure:1. Divide the red and blue litmus papers into four equal parts.2. Put a red and blue litmus paper on top of the spoon. Then, get another spoon and get a sample of detergent solution (detergent dissolved in water). Put some drops of the solution on both the blue and red litmus paper. Observe what happens. ______________________________________________________________________ ______________________________________________________________________3. Do Procedure 2 using other samples: kalamansi juice, apog in water and Seven-up or Sprite. Record all observations. ______________________________________________________________________ ______________________________________________________________________Caution: The samples that you are going to test are corrosive. Avoid contact with your skin and eyes. If the sample comes into contact with your skin or eyes, wash it right away with water! Before doing this activity, make sure that you have a litmus paper. Ask for two strips (one red and one blue) from you teacher. Are you done with Activity 3.3? Then, let us discuss your observations……Thedetergent solution and that of the apog in water changed the red litmus paper to blue. Onthe other hand, Seven-up or Sprite and kalamansi juice changed the blue litmus paper tored. When the red litmus paper changes to blue, the sample tested is said to be basic. (R-B-B) Thus, detergent solution and apog in water are both basic. On the other hand, whenthe blue litmus paper turns red, the sample tested is acidic (B-R-A). Kalamansi juice andSprite or Seven-up are both acidic. Remember that apog in water is not a base since it is not a compound. Apog is thecompound and it is the substance that is present in the mixture (apog in water) that makes itbasic. - 15 -

What you will doSelf-Test 3.3Which of the following are expected to change the blue litmus paper to red?1. vinegar Key to answers on page 19.2. kamias juice3. ammonia in water4. soap5. dalandan juice Let’s Summarize I hope that you had a great time reading and learning from this module. But moreimportantly, I hope that you learned great things about matter. So that you’ll remember andcherish what you have learned, I summarized them for you: 1. Matter is anything that has mass and volume. 2. Matter may be classified according to its composition. Under this classification scheme, matter may be classified as pure substances or as mixtures. 3. Pure substances are always homogeneous. They are made up of only one kind of matter and have a definite composition. 4. Pure substances have definite melting and boiling points. 5. Pure substances are further classified as an element or a compound. 6. Element is the simplest of matter since it cannot be broken down into simpler substances. 7. Compound is the chemical combination of two or more elements in a definite proportion by mass.PosttestMultiple Choice. Choose the letter of the best answer. Write the chosen letter on aseparate sheet of paper.1. Which of the following incorrectly describes matter?a. It has mass. c. It occupies space.b. It has volume. d. It has a definite shape. - 16 -

2. Which is an example of matter? c. light a. fire d. heat b. sound3. Which statement is NOT TRUE regarding pure substances? a. Pure substances are homogeneous. b. Pure substances have definite boiling and melting points. c. Pure substances are made up of only one kind of matter. d. Pure substances can be further broken down into simpler substances.4. At sea level, an odorless and colorless Liquid A boils at a range of 100oC to 105oC.What inference can be drawn from this observation?a. Liquid A is a metal. c. Liquid A is a nonmetal.b. Liquid A is a mixture. d. Liquid A is a pure substance.5. Which of the following are pure substances?1. gold 2. tin 3. fog 4. alloya. 1 and 2 c. 1 and 4b. 1 and 3 d. 2 and 36. Which of the following statements is true for both elements and compounds? a. They are homogeneous. b. They are the simplest form of matter. c. They are commonly found free in nature. d. They can be broken down into simpler substances.7. Copper, aluminum and gold are metals. Which incorrectly describes a metal?a. Metals are ductile. c. Metals are good insulators.b. Metals are malleable. d. Metals are good conductors of heat.8. Sulfur, carbon and the noble gases are nonmetals. Which of the following bestdistinguishes a nonmetal from a metal?a. Its homogeneity. c. Its brittleness.b. Its boiling point. d. Its ductility.9. All of the following will change red litmus paper to blue excepta. lime water c. ammonia in waterb. detergent solution d. Seven-up or Sprite10. Your chemistry teacher asked you to test Substance Y using a litmus paper. You havenoted that the blue litmus paper turns to red. This observation indicates that thesubstance isa. metallic c. acidicb. neutral d. basic Key to answers on page 19. - 17 -

Key to AnswersPretest1. b 6. a2. c 7. c3. b 8. c4. d 9. d5. c 10. dLesson 1Self-Test 1.11. Light and heat are non-examples of matter while air, water and fire are examples of matter.2. Answers may vary. The list may include pillows, candies, human beings, cats, dogs (animals in general), bed, television and many more. As long as the object occupies space and has mass then it is an example of matter.Lesson 2Self-Test 2.1 Of the samples, only Sample A is a pure substance. Based from its description, itsboiling point is definite. In addition, Sample A is a homogeneous system. Sample B is not a homogeneous system while the boiling point of Sample C is notdefinite.Lesson 3Self-Test 3.1 A B1. Fe metal2. Cu metal3. Na metal4. Mg metal5. Au metalSelf-Test 3.21, 2 and 5 are compounds. - 18 -

Self-Test 3.3 1, 2 and 5 are expected to change blue litmus paper to red.Posttest 1. d 6. a 2. a 7. c 3. d 8. c 4. b 9. d 5. a 10. cReferencesBooks:Araneta, F.L., Catris, L.V. & Deauna, M.C. (2002). The world of chemistry III. (2nd ed.) Quezon City: SIBS Publishing House, Inc.Chang, R. (2005). Chemistry. (8th ed.) New York: Mc Graw-Hill Companies.Electronic Sources (Photo Credits):http://www.surfacing-tada.com/Colour%20Summer%202003/pages/21_Dress_Hunt.htmhttp://mirel.esmartdesign.com/pages/source/9.htmwww.visionairy.com/store/foo1.htmlhttp://www.monroetwp.k12.nj.us/es/whitehall/classroom.sites/wh.classroom.htmhttp://www.naturalsci.gardner-webb.edu/Faculty/sparrish/periodic.htmhttp://www.ci.shreveport.la.us/dept/dos/graphics/house%20and%20rooms/kitchen/ vinegar.htmjapanweb.aboho.com/soy.htmfoodgoat.blogspot.com/2003/02http://simplyorangejuice.com/news.shtml - 19 -

spaghoops.com/squelch/cadbisc.htmwww.deadbus.org/archives/articleswww.venetianglassart.com/thestore/prods/SLEC-PES.htmlwww.pulaskiacademy.org/bone/Why%20do%20we%20chew%20gum.htmwww.abcusd.k12.ca.us/dist_info/nutr/A_La_Carte.htmlwww.bisondip.com/milk.asp - 20 -

Module 4 Mixed Matter What this module is about What are your favorite dishes? Are you fond of eating sinigang, bulalo, adobo,chopsuey and lumpia? What about your favorite dessert? Do you like gelatin, leche flan orbuco salad? The dishes and desserts mentioned are mouth-watering examples of mixture.Do you know what a mixture is? This module aims to guide you in describing a mixture and in classifying differenttypes of mixture. It is also designed to help you in identifying the different methods ofseparating mixtures. So, read and learn more about the following lessons:  Lesson 1 – What is a Mixture?  Lesson 2 – What are the Types of Mixture?  Lesson 3 – What are the Ways of Separating Components of Mixtures? What you are expected to learn After going through this module, you should be able to: 1. define mixture operationally; 2. cite examples of mixture; 3. name and differentiate the types of mixture; 4. classify mixture as solution, colloid or suspension based on its characteristics; 5. discuss the different ways of separating the components of mixtures; and 6. infer that useful materials can be recovered when separating mixtures. How to learn from this module I am sure that you are already eager to get started. However, there are some thingsthat you need to remember to learn most from this module.

1. Take the pre-test before proceeding to the lessons. Your score in the test will give you an idea how much time you need to devote to each lesson.2. Read the instructions and bear in mind precautionary measures.3. Before doing the activities, make sure that the materials are already prepared.4. Answer the Self-Test and compare your answers to the key to correction.5. Don’t forget to answer the post-test since it would somehow gauge how much you have learned from the module. Enjoy reading!What to do before (Pretest)A. Multiple Choice. Choose the letter of the best answer. Write the chosen letter on aseparate sheet of paper.1. Which of the following best describes a mixture? a. It exhibits Tyndall effect. b. It is a homogeneous system. c. Its components are present in fixed proportion. d. It is a physical combination of two or more substances.2. Which is an example of mixture? c. iodine crystals a. dew d. rubbing alcohol b. sugar3. Of the types of mixture, which exhibits Tyndall effect?a. colloid c. suspensionb. solution d. all of the above4. Air is to solution as ________ is to colloid.a. oil c. marshmallowb. halo-halo d. aqua oxinada5. Which does NOT belong to the group? c. mayonnaise a. smoke d. toothpaste b. soft drink -2-

B. Matching Type. Match the mixture in Column A with the separation method in Column B. Column A Column B1. Salt solution a. Evaporation2. Iron filings and sulfur b. Filtration3. Ink c. Decantation4. Muddy water d. Use of magnet5. Sweetened camote and e. Distillation f. Chromatography banana g. Hand picking/Scooping h. None of these Key to answers on page 16.Lesson 1. What is a Mixture? A Collage of the Different Samples of Mixture Mayonnaise, ink, glue, muddy water, air, smoke and chopsuey have one thing incommon. They are all examples of mixture! To give you an idea on how things around uscan be classified as mixture, why don’t you perform Activity 1.1?What you will doActivity 1.1Materials Needed: sugar glasses water fork oil teaspoon egg yolk mothballs -3-

Procedure:1. Put one teaspoon of sugar in a glass with water and then stir. Describe what happens. ______________________________________________________________________ ______________________________________________________________________2. Get another glass and fill it with water. Then, place some mothballs in it. Record your observations. ______________________________________________________________________ ______________________________________________________________________3. Mix 1 tablespoon of oil and 2 tablespoons of water. Observe. Now, add one tablespoon of egg yolk. Using a fork, continuously beat the mixture. Describe what happens. ______________________________________________________________________ ______________________________________________________________________ Have you done activity 1.1? If yes, then we may now discuss your observations… In Procedure A, what happens to sugar when mixed with water? Yes, you are right!The sugar dissolves in water. Therefore, what is in the glass is not just water but a physicalcombination of sugar and water. In Procedure B, the mothballs (naphthalene) did not dissolve in water. But just thesame, the glass does not only contain water but a combination of water and mothballs. In Procedure C, did you notice that at first, oil and water did not mix? But, when theegg yolk was added, they mixed! The egg yolk here acts as an emulsifying agent thatallows the oil and water droplets to mix and form a colloid. Sugar and water, mothballs and water, and oil and water and egg yolk have one thingin common, and that is, their components are just physically combined. In science, we callthe physical combination of two or more pure substances as mixture. You have learnedearlier in module 2 that sugar, naphthalene and water are just some of the examples of puresubstances. Can you now explain why air, salt solution, soft drinks, muddy water, and marshmallows are classified as mixtures?Other Characteristics of Mixtures Aside from mixture being just a physical combination of two or more substances, canyou cite other characteristics of mixture? Let’s find out by doing activity 1.2! -4-

What you will doActivity 1.2Materials Needed: sugar 3 glasses water spoonProcedure:1. Label the glasses as Glass A, Glass B, and Glass C.2. Fill Glass A with water and then add one tablespoon of sugar. Stir.3. Fill Glass B with water and then add a pinch of sugar. Stir.4. Half fill Glass C with water and then add one tablespoon of sugar. Stir. Glass A, B, and C contain sugar solution. However, notice that in each glass, theamount of water and sugar vary. What does this indicate? It just shows that unlike thecompounds, the components of mixture can be mixed in any proportion. Let us further examine each of the three glasses. Compare the appearances of thesugar solution in Glass A, Glass B, and Glass C. What do you observe? Yes, the mixtureare all colorless! Why? Because water is colorless. Now, why don’t you taste each of thesugar solution in the three containers? What have you discovered? Yes, they are all sweet!Why? Simply because sugar is sweet. What does this tell us regarding mixtures? Thisonly proves that the characteristics of the components of a mixture are retained in themixture.To further describe mixtures, why don’t you perform activity 1.3?What you will doActivity 1.3Materials Needed: salt spoon water casserole glassProcedure:1. Put a tablespoon of salt in a glass of water. Stir. Describe what happens to the salt. ______________________________________________________________________ ______________________________________________________________________2. Put the mixture of salt and water in a casserole.3. Heat the casserole. Caution: Be Careful!4. While heating, observe what happens to the solution. -5-

As what you have noticed, salt dissolves in water. Salt and water is more popularlyknown as salt solution and it is an example of mixture. What happens when the salt solution is heated? When the solution is heated, thewater evaporates. After some time, a white residue can be seen in the casserole. Do youknow what the white residue is? Right! It is the salt. Notice that when heat is applied tosalt solution, its components (salt and water) are recovered. What does this imply? Itimplies that mixtures can be separated by ordinary physical process i.e. evaporation. Why?Because mixture is just a physical combination of pure substances. You’ll be learning about ways of separating components of mixture in lesson 3. Remember!  Mixture is a physical combination of two or more pure substances.  The components of mixture can be mixed in any proportion.  The characteristics of the components of mixture are retained in the mixture.  Mixture can be separated by ordinary physical processes.What you will doSelf-Test 1.1Which of the following can be classified as a mixture?1. Sinigang2. Rubbing alcohol3. Vinegar4. Ice5. Copper wire Key to answers on page 16.Lesson 2. What are the Types of Mixture? Mixtures can be further grouped into three, namely: solution, colloid, and suspension.The three types of mixtures have actually been introduced in activity 1.1. Sugar solution(sugar and water) is an example of a solution whereas mothballs in water is a suspension.On the other hand, the mixture of oil, water, and egg yolk is an example of a colloid. To compare and contrast the three types of mixtures, let us perform Activity 2.1. -6-

What you will doActivity 2.1Materials Needed: flash light glue or paste salt solution 3 glasses sand in waterProcedure:1. Label the glasses as glass A, B, and C.2. Put salt solution in Glass A, sand and water in Glass B, and glue in glass C.3. Using the flashlight, let a beam of light pass through the mixture in glass A. Record your observations. ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ Note: For best results, do this in a dark room or you can do it at night.4. Repeat step 3 to glass B and C. As you have discovered in Activity 2.1, only the glueor paste scatters light. Why? Glue or paste is an exampleof a colloid. Among the types of mixtures, only colloidsexhibit Tyndall effect that is best described as the scatteringof light. This characteristic of colloid is responsible for themagnificent view that one can see when sunlight penetratesa cloud cover. Why is it that only colloids exhibit Tyndall effect? Let us carefully observe again themixtures that you have prepared in Activity 2.1……..What can you say regarding theparticles of salt in water? What about the sand in water? How about in glue or paste?On Particle Size The particles of salt are too small to be seen by thenaked eye. These particles are also uniformly distributed inwater thus a homogeneous single phase is yielded. Becauseof the smallness of the particles, the beam of light just passedthrough them. The beam of light is not that visible. Thus,scattering of light is not exhibited by solutions. Aside from sugar solution, air, salt solution and rubbingalcohol are some examples of solutions. -7-

What you will do Self-Test 2.1Can you name five more examples of solution? Key to answers on page 17. The particles of suspension (i.e. sand in water) are relatively large and are visible tothe naked eye. These particles usually settle on standing, which is a proof that it isinfluenced by gravity. Moreover, the rate of settling is dependent on particle size. Betweencoarse and fine sand, the former is expected to settle at a faster rate than the latter. Sincesuspension has more than one distinct phase, this kind of mixture is consideredheterogeneous. Now, what happens to light as it passes through a sample of suspension?Right! The light is blocked due to the relatively large size of the particles of suspension.Thus, just like solution, suspension does not demonstrate Tyndall effect. Aside from sand in water, halo-halo, sinigangand bulalo are other examples of suspension. What you will do Self-Test 2.2Can you cite 5 more examples of suspension? Key to answers on page 17. The particle size of colloids is intermediate between solution and suspension. It isnot as small as the particles of solution but not as big as the particles of suspension.Generally, the colloidal particles are ten to 100 times bigger than that of the particles ofsolution. The typical range of the colloidal particle size is from about 1 nm (nanometer) to1000 nm. These particles are evenly distributed or dispersed in another substance andunlike suspension, the particles do not settle on standing. This is because the colloidalparticles are charged and they carry the same charge. As such, they repel one another andthey do not combine to form particles that are large enough to precipitate. A simple analogythat you can think of here is when you have two magnets that are of the same pole. Do you -8-

expect them to attract one another? Of course not!Similarly, the behavior of colloidal particles would belike that of the magnets!What you will doSelf-Test 2.3Is a colloid homogeneous or heterogeneous? Briefly explain you answer. The size of the colloidal particles gives Picture of a beam of light that passescolloids some unique characteristics that can be through a sample of colloidused to distinguish them from solutions. One ofwhich is Tyndall effect. Notice that the beam oflight that passes through the sample of colloidbecomes visible. The light also becomes wider!Why is this so? The light is partially scatteredand reflected by the evenly distributed colloidalparticles. Thus, only colloid exhibits Tyndalleffect. Aside from glue, mayonnaise, gelatin and marshmallow are some examples ofcolloids. Based from these examples, it would appear that colloids are homogeneous butactually they are not. Just like suspension, colloid is made up of more than onedistinguishable phase and as such it is also heterogeneous. However, the distinguishablephases of matter in colloid can only be seen under the microscope since, as earlierdescribed, the colloidal particles are small as well. What you will do Self-Test 2.4Can you cite at least three examples of colloids? Key to answers on page 17. -9-

What you will do Self-Test 2.5Classify the following mixtures as to its type. 1. milk 2. paint 3. mongo seeds in water 4. brine 5. sago at gulaman Key to answers on page 17.Remember!  There are three types of mixtures, namely: solution, suspension and colloid.  The particles of solution are very small while those in suspension are relatively large.  The size of colloidal particles is intermediate between solution and suspension.  The size of colloidal particles gives colloid some unique characteristics that can be used to distinguish it from solution.  Only colloids exhibit Tyndall effect, which is the scattering of light.Lesson 3. What are the Ways of Separating Components of Mixtures? Do you still recall your observations in Activity 1.3? Do you still remember some keyconcepts that you have learned from the activity? Correct! In Activity 1.3, you havediscovered that salt solution could be separated into its components (salt and water). Wereyou able to recover the salt? Yes! It was the white residue left on the casserole. The whiteresidue was the same salt that you mixed with water to come up with salt solution. Whatabout the water? Were you able to recover it? You were not able to recover it since whatyou used in separating the components of salt solution was evaporation. Naturally, thewater in the solution absorbed heat and after some time it evaporated. So, the water wentinto the surroundings in the form of water vapor. From Activity 1.3, you realize that the components of mixture can be separated byordinary physical processes like evaporation. By separating mixtures, useful substancescan be recovered. For instance, if we run out of salt we can just get seawater and boil offthe water in the solution so as to recover salt which can be used as seasoning. Now, doyou want to know other methods of separating the components of mixture? Then, pleaseproceed to Activity 3.1. - 10 -

What you will do Activity 3.1Materials Needed: yellow mongo seeds green mango seeds bowl/containerProcedure:1. Put the yellow and green mongo seeds in a bowl. Then, mix them well.2. Now, think of a way by which you could best separate the yellow from the green mongo seeds. How did you separate the green from the yellow mongo seeds? Very good! Thebest way to separate them is through hand picking. Hand picking is considered as one ofthe methods of separating components of a mixture. Can you think of other mixtures thatcan be separated by the said method?..... What about halo-halo? How would you beseparating the components of halo-halo? Would you resort to hand picking? Somewhatsimilar to hand picking can be used, but instead of using your bare hands, a utensil, e.g.spoon, can be used. Thus, the process is known as scooping. What about if you have a mixture of a metallic and a nonmetallic substance? Howwill you separate them? Let us say that you have pulverized charcoal combined with verysmall pieces of copper wire, how will you separate these components? Will you be usinghand picking or scooping? Of course not! What can you use to separate the two? Right!You may use a magnet. Since one component is metallic and the other is nonmetallic, thenthe magnet will only be attracting the copper wire, and presto! The pulverized charcoal willbe left in the container. Salt solution can be separated by evaporation.However, a more appropriate method can be used toseparate its components. This method is known asdistillation. Just like evaporation, distillation is alsoused to separate solids that are soluble in a liquid. At the right is a simple distillation set-up that youcan do when you go back to school. Notice that in theset-up, the test tube containing the solution is coveredwith a cork/rubber stopper. The stopper has a hole inthe center and inserted in the hole is a glass tubing.The glass tubing maybe connected to a rubber tubingwhich in turn is placed in another test tube. Thesecond test tube, which is the receiving container, issubmerged in a beaker with cold water. Simple Distillation Set-up (Adapted from:http://www.saskschools.ca/curr_content/ science10/images/distillation.gif) - 11 -

Why should the set-up be like this? Let us say that the first test tube contains saltsolution. When heat is applied to the first test tube, the water in the solution will evaporate.Since the test tube is covered, the water vapor will not be able to escape and instead it willbe directed towards the glass tubing and eventually into the second test tube. The secondtest tube is immersed in cold water thus the temperature of water vapor is lowered until itcondenses back to the liquid phase. So, in the second test tube you are able to get backthe water. And when all the water in the solution evaporated, what will be left in the first testtube is the salt. Caution: You can do this activity in school! Make sure that the heat is applied evenlyin the first test tube or else the test tube may crack. Use only Pyrex test tubes and makesure that you seek for your teacher’s consent and supervision when doing this activity! Earlier, it was mentioned that distillation is a more appropriate method in separatingthe components of salt solution. Why? In distillation, you can recover both the salt and thewater! Mixtures that are made up of insoluble solids in a liquid can be separated byfiltration or decantation. Examples of mixtures that can be separated by the saidprocesses are muddy water and sand in water. You can do this at home! Try this and have fun! How is decantation done? For instance, you have sand in water. To separate thecomponents of this mixture, let the sand settle down. When all the particles have settleddown, carefully pour off the liquid into another container. And presto, you will be able to getback both the sand and water! What about filtration? Filtration is a process thatseparates the insoluble solid in liquid by letting it passthrough a filter paper, which is placed inside a funnel. Youmay look at the set-up below for reference. However, youcannot do this set-up at home since you may not have afilter paper. You may just do this when you go back toschool. In this setup, the small particles of the liquid willpass through the filter paper while the bigger solid particleswill be left on the filter paper. The one left on the filterpaper is the residue while the liquid that is collected is thefiltrate. (Image adapted from: http://www.tiscali.co.uk/reference/encyclopaedia/ hutchinson/images/0008n027.jpg) - 12 -

Do This! Sedimentation and centrifugation can also be used in separating mixtures, which are composed of an insoluble liquid in water. Now, why don’t you go to your library and read more about these two processes. Make sure that you’ll be able to differentiate these two from decantation and filtration. Write whatever you have discovered in a sheet of paper and submit it to your teacher. Is ink a mixture? If it is a mixture then how do we separate its components? Let usperform Activity 3.2. What you will do Activity 3.2Materials Needed: jar rubbing alcohol mimeographing paper (if this is not available, you can use an ordinary bond paper) ball pens – red and black ruler pencil pair of scissorsProcedure: 1. On the bond paper or mimeographing paper, draw a rectangle whose measurements are 6 in by 8 in. 2. Cut the rectangle. Then, draw a line 2 cm from the bottom of the rectangle. Use pencil in drawing the line. 2 cm from the bottom 3. Cut the ball point of the pen and then let the tip of the ink tube touch the line on the bond paper. Notice that you are able to put some ink. Put some more ink on the same spot and then let it dry. - 13 -

☻ 4. Do step 3 but this time use the other ball pen. 5. Then attach both ends of the paper with the use of the staple wire. Bond paper ☻ ☻ Rubbing alcohol 6. Put the paper into a jar with rubbing alcohol. Make sure that the rubbing alcohol does not touch the ink. Did you notice the different colors that make up your red ink? What about the blackink? These different colors are actually the components of the ink and you are able toseparate them by paper chromatography. Paper chromatography is a separationtechnique that uses paper as the stationary phase and a liquid solvent (in our experiment,it’s the rubbing alcohol!) as the mobile phase. The solvent is the mobile phase since it moves slowly along the surface of the paper.And since the ink spot, which is on the paper, is soluble in rubbing alcohol then the ink willbe dissolved once the solvent moves over it. The ink will move along with the solvent.Each component of the ink has its own characteristic and will be moving along the solvent atits own rate. The difference in the rates of the components of the ink makes it possible forthe components of the mixture to be separated. Let’s Summarize Did you enjoy reading the module? I hope so….Now, it is time to summarize what you have learned from the lessons and activities. 1. Mixture is a physical combination of two or more pure substances. 2. The components of mixture can be mixed in any proportion. 3. The characteristics of the mixture are a blend of the characteristics of the pure substances comprising the mixture. 4. Mixtures can be further grouped into three, namely: solution, colloid, and suspension. - 14 -

5. The particles of a solution are too small to be seen by the naked eye. Because of the smallness of the particles, the beam of light just pass through them. The beam of light is not that visible. Thus, scattering of light is not exhibited by solutions.6. The particles of suspension (e.g. sand in water) are relatively large and are visible to the naked eye. These particles usually settle on standing, which is a proof that it is influenced by gravity. Just like solution, suspension does not demonstrate Tyndall effect.7. The particle size of colloids is intermediate between solution and suspension. It is not as small as the particles of solution but not as big as the particles of suspension.8. The size of the colloidal particles gives colloids some unique characteristics that can be used to distinguish them from solutions. One of which is the Tyndall effect.9. Only a colloid exhibits Tyndall effect, which is the scattering of light.10. Ordinary physical processes like evaporation, distillation, use of magnet, hand picking, filtration, decantation, scooping and paper chromatography can be used in separating the components of mixture.PosttestA. Multiple Choice. Choose the letter of the best answer. Write the chosen letter on aseparate sheet of paper.1. Which of the following is NOT a characteristic of a mixture? a. It may be homogeneous or heterogeneous. b. Its components are present in any proportion. c. It is a physical combination of two or more elements. d. Its components can be separated by simple chemical processes.2. Which is an example of a mixture? c. table sugar a. wine d. baking soda b. table salt3. Which is an example of a suspension? c. soft drink a. glue d. muddy water b. gelatin4. Which does not belong to the group? c. Salad : Mixture a. Salt : Solution d. Muddy water : Suspension b. Gel : Colloid - 15 -

5. Which of the following gives colloids some unique characteristics that can be used todistinguish them from solution and suspension?a. Its density. c. Its boiling point.b. Its volume. d. Its particle size.B. Matching Type. Match the mixture in Column A with the separation method in Column B. Column A Column B 1. Dye a. Evaporation 2. Vinegar b. Filtration 3. Sand in water c. Decantation 4. Muddy water d. Use of magnet 5. Iron filings and powdered e. Distillation f. Chromatography charcoal g. Hand picking h. None of these Key to answers on page 17.Key to AnswersPretest Part B 1. e Part A 2. d 1. d 3. f 2. d 4. b 3. a 5. g 4. c 5. bLesson 1Self-Test 1.1 1, 2 and 3 are mixtures. - 16 -

Lesson 2Self-Test 2.1Answers may vary. Probable answers are vinegar, soft drink, bronze, jewelry, alloyand many othersSelf-Test 2.2Answers may vary. Probable answers are sago at gulaman, apog in water, bagoongna isda, gawgaw in water, black pepper in water and others.Self-Test 2.4Answers may vary. Probable answers are smoke, fog, paint, paste and others.Self-Test 2.51. colloid2. colloid3. suspension4. solution5. suspensionPosttestPart A Part B1. d 1. f2. a 2. e3. d 3. c4. a 4. b5. d 5. dReferencesBooks:Araneta, F.L., Catris, L.V. & Deauna, M.C. (2002). The world of chemistry III. (2nd ed.) Quezon City: SIBS Publishing House, Inc.Chang , R. (2005). Chemistry. (8th ed.) New York: Mc Graw-Hill Companies. - 17 -

Electronic Sources (Photo Credits):www.mayonet.com/mayonnaise.htmlwww.andersonholidays.com/html/indian_ocean.htmlwww.amc-phil.com/bulalo.htmlcooking.houseonahill.net/recipes/2003/04/000133.htmlwww.freemanriver.com/Camping_Tips/.../camping_recipes_2.htmlwww.ericksonfarms.com/storehttp://www.awqinc.com/GLOSSARY/tyndall.htmhttp://www.saskschools.ca/curr_content/science10/images/distillation.gifhttp://www.tiscali.co.uk/reference/encyclopaedia/hutchinson/images/0008n027.jpg - 18 -

Module 5 Colloids What this module is about What do milk, paints, cooked starch, ceramics, glue, ink, rubber, jelly, butter andcheese have in common? All of them are basic examples of colloids. A colloid is anothertype of mixture. It is distinguished from solutions and suspensions in that its particle size isbigger than those of solutions but smaller than those of suspensions. Colloids may appearhomogenous to the naked eye but are actually heterogenous when carefully viewed in amicroscope. This means that more than one distinct phase can be distinguished. This module is all about colloids, their properties and behavior. Knowledge of colloidchemistry can help you answer questions like How are fogs formed? Why are the sky andsea blue? What makes glue, adhesive, paint, and ink stick to surfaces? What is theprinciple behind the preparation of your all-time favorite mayonnaise spread? To make the discussion easy for you, the module is divided into four lessons:  Lesson 1 – How Do You Classify Colloids?  Lesson 2 – What are the Properties of a Colloid?  Lesson 3 – How are Colloids Prepared?  Lesson 4 – How are Colloids Utilized in Technology, Human Body and Environment? What you are expected to learn After going through this module, you should be able to: 1. classify colloids; 2. relate the properties of colloids to their behavior; 3. discuss the methods and principles applied in purifying colloids; 4. prepare colloids; and 5. explain how the properties of colloids are utilized in technology, human body and environment

How to learn from this moduleHere are some pointers to remember as you go over this module.1. Read and follow the instructions carefully.2. Answer the pre-test first before reading the content of the module.3. Take down notes and record points for clarification.4. Always aim to get at least 70% of the total number of items given.5. Be sure to answer the posttest at the end of the module.What to do before (Pretest)Take the pretest before proceeding in the lessons. Check your answers against the answerkey at the end of the module.I. Multiple Choice. Choose the letter of the best answer. Write the chosen letter on aseparate sheet of paper.1. The Tyndall effect can be used to distinguish betweena. oil and water c. solutions and colloidsb. solvents and solutes d. colloids and heterogenous mixtures2. Which of the following is a colloid? c. sand and water a. oil and water d. alcohol and water b. salt and water3. Which is NOT an emulsion? c. shaving cream a. milk d. crude petroleum b. mayonnaise4. Metal alloys belong to which type of colloid?a. sol c. foamb. gel d. emulsion5. What is the phenomenon characterized by random, zigzag movement of colloidalparticles which prevents them from settling?a. adsorption c. Brownian motionb. Tyndall effect d. electrical charge effect -2-

6. What phenomenon is observed when vapors are held on the surface of activated carbonpowder?a. adsorption c. Brownian motionb. Tyndall effect d. electrical charge effect7. Which is the process of separating ions and molecules from colloidal particles bypassing through a semi-permeable membrane?a. dialysis c. activationb. adsorption d. coagulation8. Which chemical aids in the clumping together of colloidal particles?a. ion c. coagulantb. solvent d. dispersed phase9. What is the phase of a dispersed material in Styrofoam?a. solid c. gasb. liquid d. cannot be determined10. Which of the following colloid is considered harmful?a. cheese c. whipped creamb. hair spray d. black diamondII. Matching Type. Match the description in column A with the type of colloid in column B. Column A Column B_____ 1. solid dispersed in liquid a. gel_____ 2. liquid dispersed in gas b. emulsion_____ 3. liquid dispersed in liquid c. liquid sol_____ 4. liquid dispersed in solid d. solid foam_____ 5. gas dispersed in solid e. liquid foam f. liquid aerosol Key to answers on page 17.Lesson 1. How Do You Classify Colloids? Mixtures are classified as suspensions, colloids and solutions. By now, you shouldclearly distinguish between suspensions and solutions (Module 15). The only new term toyou is just colloid. Let us check how well you can differentiate these three types of mixturesby doing Activity 1.1. -3-