Matter

Carable, John Aries Anico, Ysabella Faith Cay, Kenneth Arivalagan, Geetha Alyssa Dalangin, Luis Miguel Balmes, Romana Veronica De Jesus, Jericho Joshua Bernido, Joe-Deejaeyt Endaya, Marc Vincent S11-02 GROUP 1 LABORATORY ACTIVITY 1: WHAT IS THE MATTER WITH MATTER? A STUDY OF ITS CLASSES, CHANGES AND SEPARATION TECHNIQUES LABORATORY ACTIVITY 1: WHAT IS THE MATTER WITH MATTER? A STUDY OF ITS CLASSES, CHANGES AND SEPARATION TECHNIQUES TABLE OF CONTENTS Laboratory Report Evaluation Form 2 Introduction, Objectives, Reagents, and Materials 3 Procedures 4 Data and Results 6 Post-Laboratory/ Guide Questions 9 Conclusions and References 13 LABORATORY REPORT EVALUATION FORM Teacher Criteria Student 0 – 10 _________ Clear and Appropriate HEADING, TITLE, OBJECTIVES, and INTRODUCTION 0 - 10 10 0 - 20 _________ Appropriate presentation of DATA and OBSERVATIONS including graphs(s), chart(s), drawing(s), etc. Accuracy of data. 0 - 20 20 0 - 20 _________ Relevant and comprehensive discussion of results. The results are interpreted correctly. Presents a coherent, well-structured explanation that accounts for the results or findings of the experiment, making links between the evidence obtained and existing knowledge. Cites relevant references correctly. 0 - 20 20 0 - 5 _________ Clear and concise CONCLUSIONS. Conclusion addresses problem and states knowledge gained. Answers to all QUESTIONS. 0 - 5 5 0-10 _________ Post-lab questions are answered correctly and completely. 0-10 10 0 - 5 _________ Overall – NEATNESS, GRAMMAR, adheres to FORMAT, etc. 0 - 5 5 ______/70 _______ Total Points = Lab Grade _______ 70/70 Teacher Comments: __________________________________________________________________________ __________________________________________________________________________  LABORATORY ACTIVITY 1: WHAT IS THE MATTER WITH MATTER? A STUDY OF ITS CLASSES, CHANGES AND SEPARATION TECHNIQUES INTRODUCTION Matter is classified into pure substance and mixture. Pure substances, which are composed, of only one kind of atoms are called elements while pure substances that are combinations of 2 or more different atoms and are held together by chemical bonds are called compounds. Compounds can be further simplified into elements by undergoing chemical reactions. On the other hand, elements cannot be further simplified into a simpler form even through chemical changes and or reactions. A mixture is a physical combination of two or more pure substances wherein each substance retains its own chemical identity. Mixtures are either homogeneous or heterogeneous. Mixtures occur commonly in nature than compounds. When a new chemical substance is synthesized, for example, the substance of interest usually must be separated from various side-products, catalysts, and excess starting reagents. When a substance must be isolated from a natural biological source, the substance of interest is generally found in a very complex mixture with many other substances, all of which must be removed. Chemists have developed a series of standard methods for resolution and separation of mixtures, some of which will be investigated in this experiment. OBJECTIVES To differentiate between mixtures and pure substances. To classify the substances under study as: element, compound or mixture. To distinguish physical change from chemical change. To learn some simple separation techniques. To explain why such separations are possible relative to the physical properties of the components of a mixture. REAGENTS Sulfur powder, iron filings, sodium bicarbonate (NaHCO3), lime water [Ca(OH)2] solution, dilute hydrochloric acid (HCl) solution, naphthalene-congo red-sodium-chloride-mixture, powdered charcoal MATERIALS Ignition tube, 250 ml beaker, 10 ml graduated cylinder, test tubes, funnel, stirring rod, watch glass, medicine dropper, cotton, rubber stopper fitted with delivery tube, evaporating dish, burner, iron ring, iron stand, crucible tongs, test tube holder, wire gauze, magnet, filter paper PROCEDURE A. Pure substances and mixtures 1. Iron and Sulfur Take a small amount of sulfur and of iron filings and note down their physical properties. Test the effect of a magnet on sulfur and on iron. Place a pinch of sulfur and a pinch or iron in two separate test tubes, A and B. Add 10 drops of water to each tube and observe. Get 2 more test tubes, label them A and B again. Repeat the procedure but this time, use dilute hydrochloric acid. Observe. Mix the remaining sulfur and iron thoroughly and note the properties of the mixture. Test the effect of a magnet on the mixture. Place a pinch of the mixture in a test tube (E) and add 10 drops of water. Observe. Repeat using dilute hydrochloric acid Place the rest of the iron-sulfur mixture in test tube F. Heat strongly over a Bunsen burner flame until the residue is red hot. Cool. Note the physical properties of the mixture after heating. Test the effect of a magnet on the mixture. Note any reaction. Add 10 drops of water and observe. Discard the water and under the hood, add 10 drops of dilute HCl. What do you smell? (CAUTION: Use the proper technique for smelling gas evolved in the mixture. This is highly poisonous!) Dilute the mixture immediately with water after identifying the odor of the gas. 2. Sodium Bicarbonate and Calcium hydroxide Set up the apparatus illustrated by Figure 1a. Place about 0.5g sodium bicarbonate in a dry tube fitted with a delivery tube. Heat the tube and its contents gently and allow the gas that is evolved to bubble through 5 mL of clear lime water, Ca(OH)2. Note your observations. (Note: Remove the limewater before removing the burner). Figure 1a. An ignition tube fitted with a delivery tube. B. Separation of Mixtures Place about 1g (half a spatula) of a solid mixture of naphthalene-congo red-sodium chloride in a clean, dry evaporating dish. Cut a piece of filter paper just big enough to fit over the rim of the evaporating dish. Bore holes through the filter paper. Cover the perforated filter paper with a funnel. The tip of the funnel must be plugged with cotton. Mount the whole assembly on a wire gauze placed on an iron ring attached to an iron stand. See Figure 1b. Figure 1b. Set-up for separating mixture naphthalene-congo red-sodium chloride Slowly heat the mixture until you observe the formation of crystals on the inside of the funnel. Remove the flame and allow the set-up to cool. Observe the crystals, which form inside the funnel. List its properties. Transfer the residue remaining on the evaporating dish to a 250 mL beaker. Add 25mL water and add enough charcoal until the solution clears. Cover the beaker with a watch glass and boil for 5 to 7 minutes. Cool. While waiting for the set-up to cool, prepare the filtration apparatus. Filter the mixture and list the properties of the filtrate. Then, transfer 5mL of the filtrate to an evaporating dish and evaporate to dryness. List the properties of the residue.  LABORATORY ACTIVITY 1: WHAT IS THE MATTER WITH MATTER? A STUDY OF ITS CLASSES, CHANGES AND SEPARATION TECHNIQUES DATA AND RESULTS Pure Substances and Mixture 1. Iron and Sulfur Content(s) and Observations Test Tube A Test Tube B Test Tube E Test Tube F Iron Filings Sulfur Mixture of Sulfur and Iron Fillings (unheated) Mixture of Sulfur and Iron Fillings (heated) Physical Property (color, state, odor, texture, shape, size) Grayish-black chunky solid with metal rust like odor Yellowish solid Fine powder No odor Yellow and Black Solid with no odor While heating: Turned Red After Heating: Turned Black Solid with fart like smell Effect of magnet Obviously attracted to magnet. Magnet caused movement of the fillings Not attracted to magnet. Iron filings are still attracted to the magnet whilst sulfur is not. The difference can be told since both did not mix completely. When heated, iron filings are no more attracted with magnet, same as through with sulfur. Effect of Water Fillings does not mix with water nor dissolve in it. Sink at the bottom of the container. Sulfur floats on top of water and does not mix with it, nor dissolves in it. The iron filings sunk to the bottom while the sulfur floats at the surface. It does not mix with water, nor dissolve in it. A residue at the bottom is left. Effect of HCl Still sunk at the bottom. Oxidation might have occurred causing the filings to rust emitting a brown color. Bubbles were formed. Stays on top of HCl, does not mix with it nor dissolve in it. Bubbles were formed. Bubbles began to appear while the iron filings stayed at the bottom and sulfur stayed on top. Color changed from clear to a foggy cloud like translucent color Classification (element, compound, mixture) Iron filings added with water: Mixture Iron Filings added with HCl: Compound (A gaseous compound was formed, in form of bubbles) Sulfur added with water: Mixture Sulfur added with HCl: Mixture Iron + Sulfur + Water: Mixture Iron + Sulfur + HCl: Compound Iron Sulfide: Compound Iron Sulfide + Water/HCl: Compound 2. Sodium Bicarbonate Substance Physical Property Observations Type of Change that occurred During Heating After Heating NaHCO3 White fine powder Moisture was formed, a gaseous substance was formed. Water droplets were seen. Chemical Change Ca(OH)2 Clear Liquid Bubbles were formed. From a clear color, it turned cloudy translucent white Chemical Change Separation of Mixture Substance Physical Property Component/s Classification Crystals formed inside the funnel Dry, rough snowflake like crystals Smell a lot like moth balls/albatross. Naphthalene (C10H8) Compound Residue in the Evaporating dish Powder texture with pink and white crystal-like substance Sodium Chloride congo red Mixture Solution before adding charcoal Reddish pink with white crystal residue at the bottom Water, Sodium Chloride congo red Mixture Filtrate Clear Liquid Sodium chloride, Water Mixture Residue after heating White odorless powder Sodium Chloride Compound VI. POST- LABORATORY/GUIDE QUESTIONS: Based on the results of the activity, classify whether they are physical or chemical changes. Explain your answers briefly. In addition, if it is a chemical change write down the chemical equation that represents the reaction. CHANGE FORMULA Formation of a mixture of yellow and black solid particles by combining the yellow solid sulfur and black iron filings Physical Change. The iron filings and sulfur did not have any change in composition when combined. Production of a red solid compound by heating strongly the mixture of iron and sulfur in a test tube Chemical Change. The red solid compound is the evidence that heating iron and sulfur together changes their composition when combined. There is a change in color, the residue was neither yellow nor gray. A new substance was formed. Fe (II) + S → FeS (Iron Sulfide) Attraction of the iron filings to the magnet Physical Change. There was no change in the iron filings. It only showed reaction due to the influence of their magnetic field upon the iron (Karad, 2009). Production of bubbles when hydrochloric acid was added to the iron filings Chemical Change. The fact that a gaseous substance was formed indicates a change in chemical composition and properties. This was brought about by the reaction of iron filings to hydrochloric acid. Fe (II) (s) + 2HCl (aq) → 2H (g) + FeCl2 (aq) [Dihydrogen + Iron Chloride) Production of a pungent odor when hydrochloric acid was added to the heated iron-sulfur substance Chemical Change. The pungent odor was caused by a toxic gas, Hydrogen Sulfide, formed by adding hydrochloric acid to iron sulfide. The emission of malodorous odor, a change into a gaseous phase and composition indicates a chemical change. FeS + 2HCL → FeCl2 + H2S Formation of water droplets in the tube when sodium bicarbonate was heated Chemical Change. When the sodium bicarbonate was heated, there was a delivery tube connected to calcium carbonate (lime water). Since there was a presence of Calcium Carbonate, there is a slight change in the composition, thus, H2O would still be separated, forming water droplets composed of calcium carbonate, sodium hydroxide, and water. NaHCO3 + CaOH2 → CaCO3 + NaOH+ H2O Precipitation of white insoluble particles when carbon dioxide bubbled through the limewater Chemical Change. The white insoluble particles are Calcium Carbonate, a product produced by the reaction of carbon dioxide and limewater. Hence, the new compound is the indicator of a chemical change. Ca(OH)2 + CO2 → CaCO3 + H2O Deposition of white naphthalene flakes inside the funnel when the salt-naphthalene-congo red mixture was heated on the evaporating dish Physical Change. The naphthalene compound did not have any change in composition, it was only separated from the mixture. Clearing of the red solution when activated charcoal was added to it Physical Change. Activated carbon, or charcoal is often used as a chemical absorber. It is good in trapping other carbon-based impurities, which in this case is the congo red. Many chemicals are not attracted to charcoal, like sodium which makes it pass through when filtering (HowStuffWorks, 2000). This explains the disappearance of the red color when the mixture of red solution and charcoal was filtered. Formation of solid salt particles when the salt solution was evaporated to dryness Physical Change. When the mixture of water and sodium chloride was heated, water evaporated, leaving salt behind. The salt solution left did not have any change in composition, it only changed in state. Complete the following schematic diagram for the separation of the sodium chloride-naphthalene-congo red mixture by identifying the process and the products in each step. Naphthalene (C10H10) – Congo Red- Sodium Chloride (NaCl) Mixture CONCLUSIONS Matter can be classified into two, Pure Substances and Mixtures. A pure substance solely consists of one atom or molecule. It has the same components and properties throughout, an example would be water. In addition to this, Pure Substances are also homogeneous, which means you cannot distinguish the components from each other. On the other hand, Mixtures are combination of two or more substances, with each retaining their own properties and identities. It can be further classified as heterogeneous and homogeneous. Substances can be classified as elements, compounds, and mixtures. Element is a pure substance consisting of only one type of atom. Compound is the combination of different elements, following a certain ratio, which are chemically bonded. Mixtures are combination two or more substances not going under chemical processes. Matter can undergo physical and chemical changes. Physical changes do not change the chemical composition of a substance. While chemical change can either give or absorb energy. The latter can also produce new substances. Matter can be separated using different techniques. Some techniques require heating, adding in other substances, and more. The following are some basic separating techniques commonly used: Evaporation: used to change matter from a liquid state to a gaseous state. Filtration: uses a material to separate or purify a mixture. Gives of two substances, the residue and the filtrate. Adsorption: the process wherein atoms, ions or molecules from a substance stick to an adsorbent, after this process, filtration could be used. Separation is the way to distinguish pure substances. With this, the physical properties of the components of a certain mixture can be observed. In addition to this, the use of separation techniques can show how components/substances react to a certain change of environment. Separating mixtures often uses outside force, like heat, which can be a medium on observing the physical properties of a substance and how it reacts. References: Karad, A. (2009). Why does a magnet attract iron? Retrieved from http://timesofindia.indiatimes.com/Why-does-a-magnet-attract-iron/articleshow/4298171.cms How Stuff Works. (2000). What is activated charcoal and why is it used in filters? Retrieved from http://science.howstuffworks.com/environmental/energy/question209.htm 13