Chemistry 16 Lab Manual

Table of Contents science science science lab guard duty and Laboratory Guide profligates Common and Special Laboratory Equipment Materials and Other Requirements Common Laboratory exercises and Techniques taste 1 .. 10 Properties of guinea pig taste 2 . 12 Chemical interpolates look into 3 . 15 Classification of Matter Experiment 4 . 17 Chemical Nomenclature The Language of alchemy Experiment 5 . 22 Water of HydrationExperiment 6 . 25 Gases Experiment 7 . 27 Oxygen Experiment 8 . 29 inflame and stack Effects Experiment 9 . 31 Flame Test Experiment 10 .. 32 Electromotive Series Experiment 11 33 oxidization Reduction Re challenges/ Some Aspects of Corrosion Experiment 12. 35 Colligative Properties worldwide INSTRUCTIONS TO THE STUDENTS Apparatus Check entirely(prenominal) piece of apparatus, which you find in your storage locker from the duplicate constitute furnished to you by your teacher. Sign your adduce and submit to your instructor. The instructor signs th e checklists and gives one copy to you for your safe proceeding. ? Provide your locker with steady-going padlock. You be responsible for single the apparatus issued to you. Towards the ar anticipate of the semester you bedevil to inter variegate or give a deposit for whatever(prenominal) piece which you run with lost or broken. If you have procedureners, each of you leave alone sh ar e real bit each loss or breakage of apparatus kept in your lockers and those orrowed from the stock room. A clearance duly signed by the science science science lab attendee is a requirement for taking the final examination. NO CLEARANCE, NO final exam EXAMINATION. ? General apparatus, e. g. , Bunsen burner, thermometer, atomic number 26 stand, clamps, etc. and special apparatus whitethorn be borrowed from the laboratory attendant. ? Borrowing of apparatus from the stockroom should be do du skirt the first of all 30 legal proceeding of the laboratory period. Materials and Other Requirements You have to entrust yourself with the sideline materials and supplies besides the apparatus in the laboratory locker and the stockroom radical man-to-man feigning/ w w yap radical overworke Tissue write up Vials with cover (5 pcs) Lab nonebook Pair of scissors Rags Medicine dropper (3-5 pcs) Lab manual Aspirator Marking pens Rubber render (2 ft) Lab clothe equip gauze Filter news piece Newspaper/scratch paper Hand towel scrub bottle Tray brainchild rod Mask Liquid detergent Match Corks/rubber stoppers Goggles Test thermionic valve sponge Test pipage perceptivenesser Padlock with keys Laboratory expire Laboratory gain is an integral and essential part of any alchemy course. Chemistry is an examineal science the melds and replys that ar met in the lecture and schoolroom work has been discovered by experimental observation. The dissolve of laboratory work is to provide an opportunity to observe the reality of compounds and reactions and to learn roughlything of the trading operations and techniques. Safety is Top Priority ? All students argon required to wear a lab gown during each experiment. This bequeath be strictly obligate to avoid accidents ca employ by chemic spills and the give c atomic number 18. Safety glaze overes, goggles or center on of attention shields moldiness be worn during the experiment. Contact lenses should non be worn. ? Shorts, skirts, sandals, slippers are not abideed in the laboratory. Secure farsighted hair. ? never taste, smell, or lead a chemic dissolvent unless specifically directed to do so. Individual allergic or sensitivity responses to chemicals cannot be anticipated. If any chemical comes in contact with any other(a) part of your body or clothes, raceing thoroughly with plenty of pissing system. ? Procedures involving the liberation of volatile or toxic inflammable materials shall be per craped in a fume hood (e. g. , H2S, HCN). ? Never foment a flaskf ul or apparatus that is not opened to the atmosphere. invariably pour waste red-hot, utilize KMnO4, organic solvents and firmness of purposes of heavy coatlic elements into their keep an eye onive presidential term jars, never into the sink. ? Replace the cover of every container in a flash after removal of reagent. Deposit insoluble refuse such as pieces of paper, wood, fruitcake cork in the waste basket, never into the sink or on the adorn ? All accidents, injuries, breakages and spillages, no matter how minor, must be reported immediately to the instructor. ? Eating, drinking, smoking and playing privileged the laboratory are strictly prohibited. Your custody whitethorn be contaminated with unsafe chemicals. ? Unauthorized experiments, including variations of those in the laboratory manual, are strictly prohibited.If your chemical intuition suggests further experimentation, consult with your instructor first. ? Unauthorized person(s) shall not be allowed in the laboratory. ? Maintain a wholesome, heartfelt attitude. Horseplay and other careless acts are prohibited. ? The tab permitop must be cleared of spare materials. Put all bags and books in designated areas. ? Solids, peeing and other quiets spilled on your tabletop must be exonerateded up as currently as possible ? No electronic equipment (laptops, ipod, mp3s, cellphone, etc. ) give be switched on objet dart work in the lab. For Economic Reasons ? Always turn off the burner as soon as you are finished apply it. Get only the bill of the reagent, which you need in the experiment. economic consumption spatula for firm(a) reagents and pipet for silver-tongued ones. ? Never return any excess reagent to a bottle, unless specifically directed, to avoid befoulment Before leaving the room, see to it that ? Your locker is locked ? Your charge pissing and/or sport come onlet(s) are turned off ? The tabletop and the floor near your on the job(p) area are clean and dry Colle cting Data ? try onify all selective information as they are being collected on the laboratory notebook. Data on scraps of paper (such as jackpot bars in the balance room) bequeath be confiscated. ? recruit the information in ink as you perform the experiment. If a mistake is made in recording data, cross out the incorrect data entry with a single line (do not erase, white out or obliterate) and distinctly enter the corrected data nearby. If a large section of data is deemed incorrect, write a short notation as to why the data are in misconduct, place a single diagonal line across the data, and note where the correct data are recorded. Assessment valuation of the students progress will be sourced on performance laboratory experiments written reports of laboratory work and exams. The distribution is as follows Exams35% Performance/ Attendance15% pen Laboratory report35% Pre-laboratory write-up/ Data notebook15%Laboratory Course Policies 1. Arrive on time. The overview an d interpreting of the lab exercise, and the questions you need to answer in your written reports are grossly given at the start of each session. These could be valuable to the conquest of you laboratory course. 2. Note all laboratory rubber policies at all times. You are required to wear lab coats and safety grumpes while in the lab. You must wear your protective gear at all times that any lab work is underway. Failure to observe safety precautions may result in your being dismissed from the laboratory class. 3. entreat all chemicals and materials that you may need from the stock room at least(prenominal) 30 mins. head of the scheduled experiment. At this stage in your studies, you are expected to be able to work independently and responsibly. 4. scripted reports of laboratory work are due at the start of the following lab session. Reports that are easy will be penalized for each mean solar day of late submission(10% deduction per day). 5. Laboratory techniques, including your preparedness and participation in each laboratory activity, effective note-keeping and ability to work well with your partner will be graded accordingly. 6. Read and plan you work before every laboratory class. Prepare a pre-laboratory write-up at the start of the lab period and forward to starting your laboratory work.You will not be allowed to perform the experiment without a pre-lab write up. The pre lab should include the following sections, Experiment , patronage of Experiment, Date, Objectives of the Experiment Theoretical Framework, Materials and Methods, Expected Outcome. Sign and Date each pre-lab write-up. During the learn of the experiment, record all your raw data in the analogous notebook. 7. Written Reports should be written on a short-sized bond paper and will have the following components account, Laboratory partner/s, Discussion of Results, Calculation/s(if any), movement/s, and Answer/s, Conclusion/s, Comment on you and your partners character towards the successful completion of the laboratory activity.Submit your lab report as a convocation, write your group number and experiment number as the depicted object of the email. COMMON LABORATORY OPERATIONS AND techniqueS 1. BUNSEN BURNER A. Lighting the Burner a. seek the parts of the Bunsen burner. shed light on a sketch of the burner, cross out and state the ferment of its parts. b. Attach the rubber pipe from the burner to the hired gun outlet on the lab bench. Bring the lighted match or striker up 4-5 cm above the barrel while opening the gas valve. c. Adjust the gas supply so as to have a firing of not to a greater extent than 8 cm high. Close the air holes of the burner and observe the behavior of the shine. taste the porcelain help on this flame for a moment.What is deposited on the porcelain lot? d. Open the air holes until the flame is pale blue and has dickens or to a greater extent distinct cones. A fragile buzzing or holloa sound is characteristic of t he hot ravel flame from the burner. Too much air may blow the flame out. Adjust the air intake until the roaring stops. What is the rear on the flame upon opening of the air holes? Does this case of flame have the resembling effect on the porcelain suitcase? why? Spray close-grained charcoal on the flame and note its effect. What slangs the flame luminous? e. When the silk hat adjustment is reached, collar distinct cones are visible. Always use this large-hearted of flame unless directed otherwise. f.Extinguish the flame when it is not being apply, by finis the gas valve. B. Determining the Flame Temperatures a. Wet a piece of unreal and hold it vertically through the center of the flame, with the lower end of the cardboard resting against the top of the burner. b. Remove the cardboard as soon as it shows a tendency to char. From the scorched services note the relative temperature of the different parts of the flame. c. pass weewee a sketch of the flame to illustrate t he different regions. 2. GLASS handling A. Cutting a. Place the glass electron tube flat on the table. stool a single scratch with a sharp triangular commit 30cm from one end of the glass tubing. b.Grasp the glass tubing with both detention and place the thumbs one cm beside the scratch. Position the thumbs such that they are contrary the scratch. c. Break the glass tubing by applying a gentle pres certain(predicate). If it does not yield to gentle pressure, make a deeper scratch. d. The edges of the cut glass tubing are sharp and should be polished by rotating it at the non-luminous portion of the burners flame. This is to prevent the sharp edges of the glass from ruining corks and rubber tubing as well as cutting your fingers. B. Bending a. select a piece of glass tubing about 30 cm long and hold it lengthwise over the flame. b. To bend the glass tubing straightlacedly, it must be change uniformly over a length of 5 to 8 cm.This can be through with(p) using a flame spread er. c. Roll the tube back and forth until it has decease quite soft. d. When it has become sufficiently soft, (i. e. , the glass tubing engenders to take a pink glossiness and sag piano) take it out of the flame. e. Bend quickly to the in demand(p) incline (30 or 90) and hold until it hardens. Try to get a good idea of the angle before you begin to work so that you may work rapidly and secure the desired bend at once. f. fuddle one dear angle and one 30O bent glass tubing. throwaway Re estrusing and re-bending produces unsightly and often frail apparatus. C. Drawing Out a. Roll the center of a 10cm glass tube over the flame until it softens.The tube must be constantly rotated, to prevent the softened portion from sagging. b. Quickly ask out it from the flame, and while holding it in a vertical position, gently displace the ends apart until the bore at the stretched portion is of the desired diameter. c. Cut to the desired nozzle length and fire polish the tip. D. Boring c orks and rubber stoppers a. take aim a cork that will fit into the mouth of the flask or test tube. b. Soften by rolling it in the midst of the tabletop and the palm of your hand. burden a sharp cork borer one size low-toneder than the glass tube that will be inserted. c. Place the cork on the desk and gently twist the borer in until it is halfway through the cork.Then describe the borer and finish the hole from the other end of the cork. d. Smoo thusly(prenominal) the hole in the cork with a round file. e. If the hole is too small, have kittens it by guardedly filing with a round file. Only small adjustment should be made in this way. f. Rubber stoppers are tire in the same manner as mentioned. Select a very sharp borer one size larger than the hole to be made, and wet it with glycerin. Proceed as in boring the cork, but do not apply too much pressure. E. Inserting a glass tubing through a cork/rubber stopper NOTE This operation is the most common cause of accidents in the laboratory. a. Wet the cork and the glass tubing with water. b.Place your hand on the tubing 2-3 cm away from the stopper. shelter your hand with a towel. c. Simultaneously twist and push the tubing behind and conservatively through the hole. 3. CLEANING OF GLASSWARE a. flashy all glassware with a soap or detergent resultant. Use a brush if appropriate. b. Once the glassware is thoroughly cleaned, rinse several times with tap water and thus once or twice with di nonoperationaled water. c. Roll each rinse around the entire inner go on of the glass circumvent for a complete rinse. Discard each rinse through the preservation even out of the vessel (e. g. , beaker spout). d. Invert the clean glassware on a clean paper towel or rubber mat to dry.Do not dry any glassware over direct flame. e. The glassware is clean if, following the final rinse, no water droplets adhere to the clean part of the glassware. f. If you must use a piece of glassware while it is still wet, rinse i t with the solution to be used in the manner describe in step 5c under. 4. TRANSFERRING OF LIQUIDS/SOLUTIONS a. When the runniness or solution is to be transferred from a reagent bottle, demand the glass stopper and hold it between the fingers of the hand used to grasp the reagent bottle. Never lay the glass stopper on the laboratory bench impurities may be find faulted up and thus contaminate the liquid when the stopper is returned. b.To transfer a liquid from one vessel to another, hold a stirring rod against the lip of the vessel containing the liquid and pour the liquid down the stirring rod, which, in turn, should touch the inner rampart of the receiving vessel. Return the glass stopper to the reagent bottle. c. Do not transfer more(prenominal) liquid than is needed for the experiment do not return any excess liquid or unused liquid to the original reagent bottle. 5. meter VOLUME OF LIQUID/SOLUTIONS a. The eye should always be take aim with the meniscus when you are ma king a reading. b. For measurements of clear or transparent liquids/solutions, the multitude is read using the lower meniscus. For colored liquids/solutions, the upper meniscus is used. 6. estrus A LIQUID/SOLUTION IN A TEST thermionic vacuum tube NOTE Never fix the position of the flame at the base of the test tube and never point the test tube to anyone.The limit may be ejected violently if the test tube is not lovingnessed properly. a. The test tube should be less than one third full. Hold the test tube with a test tube holder at an angle of about 45? with the cool flame. A cool flame is a nonluminous flame supplied with a reduced amount of fuel. b. Move the test tube circularly in and out of the flame, heating from top to bottom. 7. hastiness a. Place 2 mL of atomic number 11 chloride solution in a test tube and slowly add 2 mL of smooth nitrate solution. Write the balanced chemical equation for this reaction. NOTE Be careful in handling silver nitrate solution. This sol ution may leave dark stains on skin, clothes or bench top. b.The unassailable state create is the precipitous and in this case, the slightly soluble silver chloride. reserve the abrupt to settle. c. Add a hardly a(prenominal) drops of silver nitrate solution. bear addition until no precipitation is observed. Divide the mixture into both portions and keep these for procedure 8. 8. SEPARATING A LIQUID FROM A straightforward A. Filtration a. Preparation of the extend paper to be used for gravity filtration i. Cut out a 5 x 5 piece of tense paper. Fold the filter paper in exact halves and fold it again crosswise into twain. ii. Make a small tear in one corner. This tear seals the paper against the inflow of air to the underside of the filter paper. iii.Open the folded paper so as to form a cone. iv. Place it in a displace. Moisten it with a little water and press it against the top wall of the funnel shape to form a seal. The filter paper must always be smaller than the fu nnel. v. Support the funnel with a clamp or a funnel rack. b. polish off the come formed from the previous activity by carefully pouring the mixture, with the aid of a glass rod, into the filter paper. The liquid that passes through the liquid is called the filtrate. c. The tip of the funnel should touch the wall of the receiving beaker to reduce any splashing of the filtrate. d. Fill the bowl of the funnel until it is less than two-thirds full. e.Always keep the funnel stem full with the filtrate the weight of the filtrate creates a slight suction on the filter in the funnel, thus this hastens the filtration mathematical operation. f. Set aside both set up and filtrate for the next two activities. B. effuseation a. delegate the set up retained in the filter paper into a beaker by rinse off the filter paper with jets of water from a wash bottle. b. Allow the solidness to completely settle at the bottom of the vessel for several minutes. c. budge the liquid (called supern atant) into another container with the aid of a clean stirring rod. d. Do this slowly so as not to disturb the solid. Is this method relevant for the separation of all solid-liquid mixtures? Why? e. Rinse the precipitate with water and stream again. f. Which of the two separation methods (i. e. pouration or filtration) is better in isolating the precipitate? Why? E. Evaporation a. Pour the filtrate obtained from 8A into the evaporating swear out. Place the evaporating dish on a wire-gauze supported on an iron ring clamped to an iron stand. conflagrate the dish over a cool flame. b. Continue heating until crystals begin to appear. Cover the dish with a watch glass and allow the table of content to cool. The solid remaining after evaporation is called the sleep. What is the composition of the balance? 9. slowness a. Weigh 0. 5 g of sand. Weighing may be done on platform balance or on an analytical balance. hard-bitten weighing (to the nearest half thou), can be done on the platform balance.The analytical balance is used to get more perfect mass measurements. b. The properties of the substance will often determine the genius of the container where it is to be weighed. Use a weighing paper, a watch glass, a beaker, or some container to measure the mass of the chemicals. c. Do not place the chemicals direct on the balance pan. When in doubt as to what container to use, ask your instructor. TECHNIQUE IN HANDLING CHEMICALS d. A reagent is a substance which has a expressed composition and a set of specific properties. The strong solutions are marked concentrated and the weak solutions, dilute. Some examples of the reagents are Sulfuric dotH2SO4Ammonia NH3Hydrochloric AcidHCl atomic number 11 hydroxide NaOH Acetic acidCH3COOHCalcium hydroxide Ca(OH)2 e. Before getting the desired amount, read the label twice to be sure it is the correct chemical at the right concentration. Transfer the needed amount into the receiving container. Once removed, these sh ould never be returned. f. Do not take out more than what is needed to minimize waste. Do not return excess chemicals to the reagent bottle. In pouring reagents from bottles, dont place the stopper on the table but hold it between your fingers. g. Never touch, taste or smell chemicals unless specifically directed to do so. ExPERIMENT Properties of MatterThis experiment presents several of the properties used to identify a archetype distribution of matter. The data gathered are interpreted by the use of some valued method. For safety and accuracy of results, the experimenter should make sure that all set-ups used should be properly checked for possible connection leaks and other errors. ragring rod should be used to ensure uniform distribution of heat when heating liquids in an open container. The heat should also be correct especially when heating closed set-ups. Laboratory techniques included are measurement and transferring of liquids, weighing and heating of liquids and soli ds. MATERIALS AND machine 25 or 50-mL graduated piston chamber Thermometer Cork and/or rubber stoppers 50-mL distilling flask Bunsen burner Top fill balance 250-mL beaker Rubber tubings Condenser 25-mL Florence flask squeeze stand rock oil Test tube Iron ring Sulfur powder 2-3 iron clamps Wire gauze Isopropyl alcoholic drink Lead pellets PROCEDURE 1. BOILING agitate a) Measure 25 mL of isopropyl alcohol and record the initial temperature. 32 degrees a) Transfer it into a 50-mL distilling flask. Assemble the distillation set-up (consult the instructor). b) hard the set-up gently with a Bunsen burner. Take temperature readings at one-minute time intervals until the liquid begins to boil, and two more minutes thereafter. c) Continue distilling until the flask is almost dry. Pour off the liquid still present in the flask. ) Transfer the distillate into the distilling flask and double over the distillation process. e) Make a graph of your data with time on the x-axis and temperature on the y-axis. Compare the two graphs. f) Determine the boil point of the liquid from the graphs. Look for the standard boiling point of isopropyl alcohol and get the % error of the boiling point obtained experimentally. 2. MELTING POINT a) Place about 1-gram of south powder into a dry test tube. Clamp the test tube vertically into the oil bath. See to it that the solid is below the oil level. a) touch the thermometer into the test tube such that it is covered by the solid and does not touch the sides and bottom of the test tube. ) Heat the oil bath little by little and take temperature readings at one-minute intervals until the solid has completely liquefied, and two more minutes thereafter. c) Make a graph of your data with time on the x-axis and temperature on the y-axis. Determine the dissolve point of sulfur from the graph. Look for the standard melting point of sulfur and get the % error of the melting point obtained in the experiment. NOTE Stir the oil bath s o that the heat is uniformly distributed. 3. DENSITY OF A LIQUID a) Clean and dry the Florence flask. Weigh the dry flask and the rubber stopper on a top essence balance and record the mass. b) Fill the flask with distilled water until the liquid level is nearly to the brim.Put the stopper on the flask in order to drive all the air and excess water. Work the stopper gently into the flask so that it is firmly seated into position. c) Wipe any water on the outside of the flask and soak up all excess water from around the top of the stopper. d) Again, weigh the flask, which should be completely dry on the outside and full of water, and record the mass. e) Calculate for the precise volume of the flask given the standard engrossment of water, the temperature of the laboratory and the mass of water in the flask. f) Empty the flask, dry it and fill it with isopropyl alcohol. Stopper and dry the flask as you did when working with water. memorialize the weight of the flask filled isopropyl alcohol. g) Calculate the density of isopropyl alcohol and determine the % error using its standard density. 4. DENSITY OF A SOLID a) Use the same flask from the previous procedure for this part. Dry the flask completely and add small chunks of lead coat into the flask until it is about half full. b) Weigh the flask, with its stopper and the metal, and record the mass. Determine the mass of the metal in the flask. c) Fill the flask with water, leaving the metal in the flask, and then replace the stopper. Roll the metal around the flask to make sure that no air is trapped between the metal pieces. ) Refill the flask if necessary, and then weigh the dry stoppered flask full of water plus the metal sample. e) Compute for the density of the lead using the data obtained in this section and in part 3. Determine the density of the metal and compute for the % error. QUESTIONS 1. Interpret the graphs obtained in parts 1 and 2. What changes occur at the different regions of the graph? 2. W hat kind of properties are boiling point, melting point and density? 3. Which of these properties may be used to identify a sample of matter? Why? 4. Is one property sufficient to establish the density of the substance? 5. What is the identity of the distillate in Part 1? What is your keister?ExPERIMENT CHEMICAL CHANGES This experiment presents different types of chemical change. Some quantitative methods are included to emphasize proper data handling and interpretation of results. Formula writing and setting up of simple chemical equations are introduced. It is to be emphasized that the experimenter should always take note of any sensible evidence that a chemical reaction is taking place. Such corporal evidences include the formation of a precipitate, change in color of the solution or precipitate, evolution of a gas, and absorption or evolution of heat. ? ontogenesis of gas. This evolution may be quite rapid or it may be a fizzing sound. Appearance or Disappearance of precipit ate. The nature of the precipitate is important it may be crystalline, it may have color, it may merely cloud a solution. ? Evolution or Absorption of Heat. The reaction vessel becomes warm if the reaction is exothermic or cools if the reaction is endothermic. ? Change in color. A substance added to the system may cause a color change. Also included are the common laboratory operations such as measurement and transferring of liquids, precipitation, decantation, filtration, washing and transferring of precipitates, drying of solids, weighing, scrutiny for acidity and basicity, and testing for completeness of a reaction.This experiment also emphasizes the need for gradual mixing of reactants to make certain the maximum recovery of the product, and the importance of washing, to ensure the purity of the product. MATERIALS AND APPARATUS 50-mL graduated cylinder Watch glass Zinc dust 250-mL beaker Evaporating dish 0. 100 M Cu(NO3)2 250-mL Erlenmeyer flask Pair of scissors 6. 00 M NH3 move Filter paper 6. 0 M NaOH Bunsen burner Litmus paper 6. 00M HCl Stirring rod Medicine Dropper 6. 00 M H2SO4 PROCEDURE 1. haste of Copper (II) hydroxide a) Measure 10-mL of 0. 100 M Cu(NO3)2 solution in a 250-mL beaker. a) Add dropwise with constant stirring about 0. 5 mL 6. 00 M NaOH solution. b) Place a piece of litmus paper on a dry watch glass and moisten it with the solution using a stirring rod. c) If it is not yet alkaline, add more NaOH. Record any change in color of the solution and describe the precipitate. 2.FORMATION OF cop (II) OXIDE a) Boil the contents of the beaker in part 1 for about 2 minutes with constant stirring to prevent bumping which may result in loss of material. The precipitate should change in color. b) Allow the copper (II) oxide precipitate to settle. Take note of the change in color of the precipitate. c) Test the supernate with a few drops of 6. 00M NaOH. If cloudiness is observed, continue the addition of the base until precipitation is comp lete. d) Heat the solution again with constant stirring, until all the precipitate has changed in color. Record the color changes that occur. What is the evidence of complete precipitation?What is the composition of the supernate? 3. CONVERSION OF strapper (II) HYDROXIDE TO COPPER (II) SULFATE a. Let the precipitate settle until the supernate is clear. Decant the supernate through a filter paper into the Erlenmeyer flask. b. lick the precipitate in the beaker using 10 mL of water. Let the precipitate settle and decant the wash water through the filter paper into the Erlenmeyer flask containing the filtrate. c. replicate the process, so that the precipitate is washed a total of four times. d. Wash the same filter paper with about 1 mL 6. 00 M H2SO4 dropwise, catching the filtrate in the beaker containing copper (II) oxide precipitate. e.Rotate or stir the contents of the beaker to dissolve the solid. Add some more H2SO4 to dissolve the precipitate completely. f. Wash the filter pa per again, this time with 10 mL water, catching the wash water in the same beaker. Record your observations. 4. REDUCTION OF Cu (II) IONS TO all-metal COPPER a. To the solution (from 3), gradually add with constant stirring, about 1. 5 g surface dust in minute amounts. CAUTION Stir until no further reaction is observed before adding more atomic number 30 to make the solution colorless. b. Test for the completeness of the reaction by adding a few drops (1-2 drops) of the solution into a test tube containing about 1 mL of 6. 0 M NH3. If a colored solution is obtained, differentiate this with the visit solution (prepare by adding a drop of 0. 100 M Cu(NO3)2 solution and 2 drops of NH3 to 1 mL water) and add more zinc into the solution with constant stirring. Repeat the process until the test with ammonia solution gives a colorless solution. c. Decant and discard the supernate in 4-b. Wash the precipitate in the beaker twice, each time using 10-mL portions of water. Decant and disca rd the wash water after each washing, taking care not to lose any solid. d. To the precipitate, add 10 mL water and 2 mL 6. 00 M HCl slowly and stir the contents until no more change is observed.Let the precipitate settle, decant and discard the supernate into a waste acid jar. e. Wash the precipitate twice, each time using 10-mL portions of water. Decant and discard the wash water. f. Transfer the entire solid in the beaker to a previous weighed filter paper. Use as little water as possible to wash out the solid from the beaker. Discard the filtrate and wash water. g. Fold the filter paper containing the solid and press this between pieces of dry filter paper to remove most of the water. Place the partially dried filter paper containing the solid on a watch glass, and air dry in your locker until the next period. Weigh the solid and the filter paper.Record all masses obtained. 5. oxidisation OF COPPER a. Place a pinch of the weighed solid in an evaporating dish and heat the dish d irectly over a Bunsen burner. hold back and record your results. b. Submit the remaining solid, properly packaged and labeled, to your instructor. QUESTIONS 1. What type of process and/or chemical changes is observed in procedures 1-5? 2. Why must zinc be added very gradually to the solutions in procedure 4. a? 3. What is the purpose of the test using ammonia solution? 4. Why must HCl be added to the solid after the reaction with zinc dust is completed? 5. Why is it not advisable to dry the copper directly over a Bunsen flame? 6.Calculate the percent recovery in the experiment. Does your result renounce the law of conservation of matter? Explain. ExPERIMENT CLASSIFICATION OF MATTER Matter is classified according to its various properties and the type of changes it undergoes. There are two general types of matter, substances and mixtures. Substances are further subdivided into two types, elements and compounds. Mixtures are also of two kinds, self-colored and heterogeneous. This e xperiment aims to differentiate several samples of matter. The samples are subjected to different conditions like temperature and solubility in some solvents. Chemical changes are illustrated by chemical equations. MATERIALS AND APPARATUS Beakers Evaporating dish Sugar crystals 250-mL Erlenmeyer flask Test tubes atomic number 11 chloride funnel Thermometer Iodine Crystals Bunsen burner Mortar and Pestle Sulfur powder frosting tubing Filter paper Lead (II) nitrate Watch glass Litmus paper Magnesium ribbon Medicine dropper amylum solution PROCEDURE 1. ubstances, homogeneous and heterogeneuos mixtures a. Measure out one gram of refined cole in the balance. Dissolve the sample in 50 mL tap water. Compare the appearance of the solution with that of distilled water. Set up a simple distillation apparatus using the Erlenmeyer flask, thermometer and glass tubing. b. ameliorate the sugar solution and make a boiling point pervert on the graphing paper. Collect the sugar solutio n and make a boiling point curve of the isopropyl alcohol (from experiment 1). Compare the boiling point curve of the sugar solution with that of the isopropyl alcohol. Which of the two is a substance and which is a mixture? c.Test for the solubility of the powdered sulfur in water. Do the same with sodium chloride. Weigh out 0. 5 g of each chemical on the analytical balance. d. Grind the two together in a mortar. Note the appearance of the mixture. With a hand lens, observe the mixture more closely. Can you distinguish the sulfur from the sodium chloride crystals? e. Transfer half of the mixture into a beaker containing about 15 mL of water. Stir thoroughly then filter the resulting mixture. Identify the filtrate and the residue on the filter paper. f. Transfer the filtrate into an evaporating dish. Heat this to boiling. When the crystals begin to form, cover the dish with watch glass to prevent sputtering.When the crystals are almost dry, stop heating the dish. g. Heat the other h alf of the original mixture in an evaporating dish until melting is observed. hear the resulting product closely using a hand lens. Can you at once differentiate the two components? Test its solubility in water. Record all observations. 2. ELEMENTS AND COMPOUNDS a. Take two small crystals of iodine. Place one crystal inside the test tube and heat it gently. Compare the heated and the unheated crystals with respect to state, color, solubility in water and their behavior in starch solution. b. Take a pinch of lead nitrate crystals. Observe carefully and list down its observable physical properties.Heat it over a burner, gently at first, and then strongly afterwards until no further change is observed. sway down your observations. 3. METALS AND NON-METALS a. Clamp a medium-sized test tube horizontally. Take a piece of atomic number 12 ribbon and insert one end into a 10-cm piece of glass tubing. b. Heat the magnesium ribbon. When it begins to burn, insert the burning magnesium ribbo n into the test tube until the metal has burned completely. c. Dissolve the residue in 3-mL water. Test the acidity and basicity of the solution with litmus paper. Repeat using a pinch of sulfur. QUESTIONS 1. Write all chemical equations involved. 2. Does the appearance of the sugar solution differ from that of distilled water? 3.In part 1, which is an example of a homogeneous and heterogeneous mixture? How are the two types of mixtures differentiated? 4. What is the composition of the crystals formed after evaporation of the filtrate in 1. b? 5. Based on the results of part 1, how are substances different from mixtures? 6. Is there any evidence that would delegate a change in the identities of each of the substances heated? What are these evidences? 7. brand the oxides of metals and non-metals. 8. From the results in part 2, define elements, compounds, metals and non-metal. 9. Iodine is liberated from seaweeds by the action of sulfuric acid on the ash of the seaweeds. How is it c ollected from the ashes? ExPERIMENTThe Language of Chemistry Chemical Nomenclature Chemical Nomenclature is the system of naming substances. A systematic nomenclature was established by an organization of chemists called the International sum of money of Pure and Applied Chemistry (IUPAC). The standardized rules developed by the IUPAC are summarized below. 1. binary star Compounds 1. 1 Binary Compounds Containing Two Nonmetals If two nonmetals form a compound, the less electronegative is written first, followed by the more electronegative element. The same pattern is used in naming the less electronegative is mentioned first, followed by the stem of the abduce of the more electronegative ending in ide.When more than one compound can be formed from the combination of two elements, Greek prefixes are used to indicate the number of atoms of each element. carbonic acid gas carbon dioxide PCl3 phosphorous trichloride Cl2O Dichlorine mon(o)oxide* HCl Hydrogen chloride *this is omit ted when the more electronegative element begins with a vowel Greek Prefix event Greek Prefix cast Mono- 1 Hexa- 6 Di- 2 Hepta- 7 Tri- 3 Octa- 8 Tetra- 4 Nona- 9 Penta- 5 Deca- 10 1. 2 Binary Compounds Containing a alloy and a Nonmetal The metal is always written first, in both the phone and the formula. As with all binary compounds, the nonmetal takes an ide ending.There are two types that we must consider metals with fixed (only one) oxidation number and those with variable star (more than one) oxidation numbers. 1. 2. 1 Cations Monatomic ions cations retain their names as elements. The NH4+ ion, ammonium ion is named as if it were a metal ion because of its sodium chloridelike properties. Li+ lithium ion Na+ sodium ion Mg2+ magnesium ion Al3+ aluminum ion 1. 2. 2 Monatomic AnionsMonatomic anions are named using their names as elements and the suffix ide. C4- carbide N3- nitride O2- oxide H- hydride 1. 2. 3 Metals with Fixed Oxidation song The metals w ith fixed oxidation numbers are the IA and IIA, Aluminum and Zinc. All other metals have variable oxidation numbers. Note that no prefixes are used. NaCl Sodium chloride Na2S Sodium sulphide AgBr silver bromide Al2O3 aluminum oxide 1. 2. 4 Metals with Variable Oxidation Numbers In a binary compound of a metal of this type with a nonmetal, the oxidation number of the metal must be indicated in the name. There are two methods of doing this, the unmixed system and the nervous strain or Roman numeral system. 1. 2. 4. Classical System This system can only be used for metals having two oxidation states. An ic ending is used for the metal with the highest oxidation state and an ous ending is used for the lowest. Also, the Latin name is used for iron (ferric and ferrous), copper (cupric and cuprous), tin (stannic and stannous) and lead (plumbic or plumbous). The classical system does not indicate the actual oxidation state. 1. 2. 4. 2 armoury System or Roman Numeral System The actual oxidation state is designated by a Roman Numeral placed in parenthesis immediately following the name of the metal. This is useful especially if the metal has more than two oxidation states. Formula Classical System Stock System CuCl Cuprous chloride copper(I) chloride CuCl2 Cupric chloride copper(II) chloride FeCl2 ferrous chloride iron(II) chloride FeCl3 ferric chloride iron(III) chloride 1. 3. Compounds Named Like Binary Compounds Few other compounds take an ide ending, like binary compounds. These include the following OH- hydroxide O22- peroxide CN- cyanide NH2- amide I3- triiodide N3- azide 1. 4. Trivial Names Some common binary compounds are assigned trivial names that have been assigned arbitrarily. These are universally used that they are allowed by the IUPAC rules of nomenclature. H2O water NH3 ammonia PH3 phosphine AsH3 arsine 1. 5. Binary Acids A binary compound composed of atomic number 1 with a more electronegative element can act as a binary acid in w ater solution. For acids of this types, the prefix hydro- is added, and then the ide ending is replaced by ic acid. HF hydroflouric acid HCl hydrochloric acid HBr hydrobromic acid HI hydroiodic acid 2. Ternary and Higher Compounds 2. 1 Oxyacids and Salts Oxyacids are composed of a nonmetal with more than one oxidation state, along with total heat and oxygen. A salt of oxyacid is formed when one or more of the hydrogen ions of an acid is replaced by a cation. The prefix hypo-, is used to look up the lowest oxidation state of the nonmetal with the characteristic ending ous and the prefix per- is used to denote the highest oxidation state with the ending ic. For acids whose names end in ous, the corresponding salt ends with the suffix ite, and those whose names ends in ic, the name of the salt ends in ate. Acid Oxyanion Salt H2SO3 sulfurous acid SO32- sulfite Na2SO3 sodium sulfite H2SO4 sulfuric acid SO42- sulfate Fe2SO4 iron(II) sulfate HClO hypochlorous acid ClO- hypochlorit e NaClO sodium hypochlorite HClO2 chlorous acid ClO2- chlorite KClO2 potassium chlorite HClO3 chloric acid ClO3- chlorate NaClO3 sodium chlorate HClO4 perchloric acid ClO4- perchlorate NaClO4 sodium perchlorate 2. 2 Salts of Polyprotic Acids These types of salts are formed when one or more hydrogen ions in polyprotic acids or acids with more than one replaceable H+ ion (e. g. , H2S, H3PO4, H2SO4) is/are replaced by metal ions. In naming, the word hydrogen is added to the name of the oxyanion. NaH2PO4 sodium dihydrogenphosphate Na2HPO4 disodium hydrogenphosphate Na3PO4 trisodium phosphate NaHS sodium hydrogensulfide EXERCISES 1. Name the following. a. FeI2___________________________________ b. I2___________________________________ c. FeCl3___________________________________ d. Fe2(SO4)3___________________________________ e. FeS___________________________________ f. NCl3___________________________________ g. H2CO3___________________________________ h. CaCO3_____________________ ______________ i.Be2C___________________________________ j. SnSO4___________________________________ k. (NH4)2S___________________________________ l. N2O4___________________________________ 2. Write the correct chemical formula a. Barium chloride___________________ b. stannic nitrate___________________ c. Stannic nitrate___________________ d. Aluminum carbide___________________ e. Magnesium phosphate___________________ f. Nitrogen dioxide___________________ g. Ammonium sulfate___________________ h. Barium carbonate___________________ i. Sodium carbonate___________________ j. Calcium hydrogen phosphate___________________ k. Disulfur dichloride___________________ 3. Complete the following table Formula Name as acid Formula of sodium Name of salt salt HNO3 HNO2 HBrO HBrO2 HBrO3 NaBrO3 HBrO4 4. Name the following as binary compounds or as salts from the anions of polyprotic or oxo acids. a. NaIO___________________________________ b. K2HPO4____________________ _______________ c. Na2SO3___________________________________ d. KMnO4___________________________________ e.BaSO3___________________________________ f. FeSO4___________________________________ g. HClO3___________________________________ h. Na2SO4___________________________________ i. Fe(NO3)3___________________________________ j. Ca(ClO2)2___________________________________ 5. The spaces below represent portions of some of the main groups and periods of the periodic table. In the proper squares, write the correct formulas for the chlorides, oxides and sulfates of the elements of Groups 1, 2 and 3, respectively. Likewise, write the formulas of the compounds of sodium, calcium and aluminum with the elements of Groups 6 and 7. Two of the squares have been completed as examples. Period Group 1 Group 2 Group 3 Group 6 Group 7 2 LiCl (Omit sulfate) Li2O Li2SO4 3 Na2S CaS Al2S3 4 5 ExPERIMENT water supply OF HYDRATI ON Most solid chemical compounds will contain some water if they have been exposed to the atmosphere for any length of time.In most cases the water is present in very small amounts, and is mere adsorbed on the surface of the crystals. Other solid compounds contain larger amounts of water that is chemically butt against in the crystal. These compounds are usually ionic salts. The water that is present in these salts is called the water of hydration and is usually bound to the cations in the salt. In this experiment you will study some of the properties of hydrates. You will identify the hydrates in a group of compounds, observe the reversibility of the hydration reaction, and test some substances for efflorescence or deliquescence. Finally you will be asked to determine the amount of water lost by a sample of unknown hydrate on heating.From this amount, if given the formula or the molar mass of the anhydrous sample, you will be able to depend the formula of the hydrate itself. MATE RIALS AND APPARATUS watch glass iron ring melting pot tongs test tubes iron stand triangular clay Bunsen burner crucible desiccators PROCEDURE 1. Identification of Hydrates. Place about 0. g of the compounds listed below in small, dry test tubes, one compound to a tube. Observe carefully the behavior of each compound when you heat it gently with a burner flame. If droplets of water condense on the cool upper walls of the test tube, this is evidence that the compound may be a hydrate. Note the nature and the color of the residue. Let the tube cool and try to dissolve the residue in a few cm3 of water, warming very gently if necessary. A true hydrate will tend to dissolve in water, producing a solution with a color very similar to that of the original hydrate. If the compound is a carbohydrate, it will give off water on heating and will tend to char.The solution of the residue in water will often be caramel colored. Nickel chloride Potassium chloride Sodium tetraborate (borax) sac charose Potassium dichromate Barium chloride 2. Reversibility of Hydration. Gently heat a few crystals 0. 3 g, of hydrated cobalt (II) chloride, CoCl2(6H2O, in an evaporating dish until the color change appears to be complete. Dissolve the residue in the evaporating dish in a few cm3 of water from your wash bottle. Heat the resulting solution to boiling (CAUTION ), and carefully boil it to dryness. Note any color changes. Put the evaporating dish on the lab bench and let it cool. 3. Deliquescence and Efflorescence.Place a few crystals of each of the compounds listed below on separate watch glasses and put them next to the dish of CoCl2 prepared in Part B. Depending upon their composition and the relative humidity (amount of moistures in air), the samples may gradually either lose water of hydration to, or pick up water from, the air. They may also remain unaffected. Any changes in crystal structure, color, or appearance of wetness should be noted. Observe the samples occasionally du ring the rest of the laboratory period. Since the changes tend to occur slowly, your instructor may have you compare your samples with some that were set out in the laboratory a day or two earlier. Na2CO3(10H2O (washing soda) CaCl2KAl(SO4)2(12H2O (alum) CuSO4(5H2O 4. Percent Water in a Hydrate. Clean a porcelain crucible and its cover with 6 M HNO3. Any stains that are not removed by this treatment will not inject with this experiment. Rinse the crucible and cover with distilled water. Put the crucible with its cover slightly ajar on a clay triangle and heat with a burner flame, gently at first and then to redness for about 2 minutes. Allow the crucible and cover to cool, and then weigh them to 0. 001 g on an analytical balance. Handle the crucible with clean crucible tongs. Obtain a sample of unknown hydrate from the stockroom and place about a gram of sample in the crucible.Weigh the crucible, cover, and sample on the balance. Put the crucible on the clay triangle, with the cover in an off-center position to allow the escape of water vapor. Heat again gently at first and then strongly, keeping the bottom of the crucible at red heat for about 10 minutes. Center the cover on the crucible and let it cool to room temperature. Weigh the cooled crucible along with its cover and contents. Examine the solid residue. Add water until the crucible is two thirds full and stir. Warm gently if the residue does not dissolve readily. Does the residue appear to be soluble in water? DATA AND OBSERVATIONS A. Identification of Hydrates Water appears modify of residue Water soluble Hydrate Nickel chloride Potassium chloride Sodium tetraborate Sucrose Potassium dichromate Barium chloride B. Reversibility of Hydration Summarize your observations on CoCl2(6H2O. Is the drying up and hydration of CoCl2 reversible? C. Deliquescence and Efflorescence Observation Conclusion Na2CO3(10H2O CaCl2 KAl(SO4)2(12H2O (alum) CuSO4(5H2O D. Percent wat er in a Hydrate plenitude of crucible and cover Mass of crucible, cover, and solid hydrate Mass of crucible, cover, and residue Mass of solid hydrate Mass of residue Mass of water lost Percentage of water in the unknown hydrate Formula mass of anhydrous salt (if furnished) Number of moles of water per mole of unknown hydrate ExPERIMENT GASESThis experiment illustrates three of the common gas laws Boyles law, Charles and Gay-Lussacs law and Grahams law. Boyles law states that the volume, V, of a certain quantity of an ideal gas is inversely proportional to its pressure, P, at a given temperature and amount of gas. Charles and Gay-Lussacs law states that the volume of a gas is directly proportional to the inviolate temperature, at a certain pressure and amount of gas. Grahams law describes that the velocity of an ideal gas is inversely proportional to the square root of its molar mass. The first two gas laws will be validated using plots of the properties involved. Grahams law will be determined by comparing the velocities of two sample gases. MATERIALS AND APPARATUS glass syringe 250 or 400-mL beaker Black cardboard Syringe holder Iron stand Ruler Thermometer Iron ring Graphing paper Glycerol Wire gauze Concentrated HCl Modeling clay Glass tubing