Moles



Honors ChemistryLab ManualUnit 4MolesMolesUnit 4MolesUnit 4Upon Completion of the labs and activities within this unit you will be able to…Perform one step molar conversions (mass?moles, particles?moles, L?moles)Perform multi-step molar conversions (particles?mass, L?particles, L?mass)Determine the % composition of various compoundsCalculate the empirical and molecular formulas for various compounds (including hydrates)1434465831850045186601333500-21272517145000-23495016065500475170515176500-14287519875500MolesUnit 4Lab: Candy MolesYummy Candy Company has standardized the serving size of all their varieties of candies to “1 Mmmmmmmmmm”.Candy land uses Mmmmmmmmmm as a standard and accepted measurement to count amounts or numbers. We have been told that:1 Mmmmmmmmmm = 8 piecesThe FDA (Food and Drug Administration) has mandated all food makers to label their serving sizes in grams as well. Yummy Candy Company has hired me to compile a team to determine the grams per 1 Mmmmmmmmmm for all their varieties of candies. You will be acting as a member of my team to determine this factor.We have been given three brands of candies:BrandSize (approx.)Mass (g) of 1 MmmmmmmmmmGummy CandyM & M’sStarburstsProcedure:Transfer 1 Mmmmmmmmmm of each candy into its own container (Dixie? cup)Use the empty cup by the balance to zero out the balancePlace your cup with 1 Mmmmmmmmmm of candy in it on the balance & record the massRepeat for each type of candyAnalysis Questions: You must show your work for all calculations or lab will be given ZERO credit!Which type of candy had the greatest mass per 1 Mmmmmmmmmm? The least? Why does this make sense?If you were measuring a chemical substance, what unit of measurement would you use and why? (Think: what do scientists use to measure an atom, compound, etc.?)MolesUnit 4If each individual candy is a particle, how many particles are present per unit (1 Mmmmmmmmmm) of the above chemical measurement?How many grams of M&Ms would be in 3.5 Mmmmmmmmmm’s? (Show your work!)If you eat 6.3 g of Starbursts, how many servings have you had (remember: the serving size = 1 Mmmmmmmmmm)My student Cindy is a big fan of gum drops, the other day she ate 53, how many grams was that?How do you think this lab relates to how scientists use the mole? (Write at least four well thought out, complete sentences )MolesUnit 4Lab - What Does A Mole Look Like? Counting the individual items in a group as large as the mole is impossible. As a result, a different method is used to count a mole of molecules – counting by weighing. The same process is used to count aluminum cans when you take a bag to the recycling center. A conversion factor (weight per can) is used to convert the weight of the bag into the number of cans in the bag. In the same way, the molar mass of an element or compound is used to convert the mass of a sample into the number of atoms or molecules in that sample.In this lab, you will perform molar conversions for small samples of three everyday substances, water, chalk, and aluminum.PROCEDUREFill a paper cup with water and measure its mass. Drink one mouthful of water and find the new mass of the paper cup. Record the initial and final masses in your data table. The measurements you will need to record in order to calculate the moles of water consumed are as follows: (Note all measurements should be recorded in a properly labeled data table on your poster (see other side)).Measurement DescriptionActual Measurement (watch sig. figs.!)AMass of water gBMass of water after drinking one sip gCMass of water consumed gDMoles of water consumed (show work below)molsEMolecules of water consumed (show work below) m’cObtain a piece of chalk (calcium carbonate). Wipe it free of dust particles and measure its mass. Write a message with the chalk and find its new mass. Record the initial and final masses in your data table. The measurements you will need to record in order to calculate the moles of chalk consumed are as follows: (Note all measurements should be recorded in a properly labeled data table on your poster (see other side)).Measurement DescriptionActual Measurement (watch sig. figs.!)AMass of chalkgBMass of chalk after writing messagegCMass of chalk consumed gDMoles of chalk consumed (show work below)molsEMolecules of chalk consumed (show work below) m’cMolesUnit 4How thick is aluminum foil in centimeters? How many atoms thick is this? The small size of any one atom gives a clue to the relatively large number of atoms in a sample of matter that we can pick up and measure. The size of an aluminum atom was measured by a process called x-ray diffraction and found to be about 2.5 x 10-8 cm long. The purpose of this part of lab is to relate the size of an aluminum atom to the thickness of a piece of aluminum foil. In order to find the thickness in terms of atoms you will need to know the density of aluminum, 2.70g/cm3, and compute the thickness of your piece of foil.Obtain a piece of Aluminum foil from the teacher. Measure and record the length and width of the square to the nearest 0.1cm. Find the mass of the foil. Return the foil to the teacher. The density of Al is 2.70g/cm3. The measurements you will need to record and compute to determine the thickness of the foil in terms of atoms are as follows: (Note all measurements should be recorded in a properly labeled data table on your poster (see other side)).Measurement DescriptionActual Measurement (watch sig. figs.!)ALength of Al foilWidth of Al foilcmcmBDensity of Alg/cm3CMass of Al foilgDVolume of Al foil (show work below)cm3EHeight of Al foil (show work below) cmFAtoms thick of Al foil (thickness of 1 Al atom = 2.5 x 10-8 cm: show work below)atomsGMoles in Al foil (show work below)molsHAtoms in Al foil ( show work below)atomsMolesUnit 4QUESTIONS – Answer in complete sentences!!Identify the conversion factors you used and specify how you used them.If you consume 5 grams each of water, chalk, and Aluminum, will you consume more water molecules, more chalk molecules, or more Aluminum atoms? Explain.If you consume 5 moles each of water, chalk, and Aluminum, will you consume more water molecules, more chalk molecules, or more Aluminum atoms? Explain.If the population of the world is 5.6 x 109 individuals, how many atoms of aluminum could you distribute to each person from your sample of aluminum foil?MolesUnit 4Lab – Isn’t Chemistry Sweet !!Supplies: Sugar (sucrose C12H22O11)Disposable Beaker (plastic cup)Disposable Scoopulas (spoons)Chemistry Flavor Crystals Procedure: Use the calibrated cups at the front of the room to mark your beaker with a pen at the 250 ml line.Using your beaker, mass out 0.0725 moles of sucrose.Add water to the 250 ml line.Stir in a dash of chemistry crystals.Drink the chemistry, live off the chemistry, BE THE CHEMISTRY!Pre-Lab Questions:After reading through the procedure I hope you’ve realized that in order to correctly make your “Chemistry” mixture you need to measure out a specific amount of sucrose…What units did I give you to use when measuring out sucrose?Can you use our balances to measure this amount as is?What do you need to convert the original unit to?How will you do this (set up the correct dimensional analysis to go from moles of sucrose- C12H22O11 to grams)How many grams of sucrose will you need to mass out (answer to calculating set up of #4)?MolesUnit 4544558310295900Lab: Percent Sugar in Bubble Gum Problem: What percent of bubble gum is sugar? Materials:5 pieces of sugared bubble gumpaper cupbalanceProcedure:Use a balance to determine the mass of a clean paper cup. Record the mass in your data table.Unwrap 5 pieces of bubble gum containing sugar and place them in the cup.Determine the mass of the cup and the gum. Record the mass in your data table.Each person in the group should chew a piece of gum to remove the sugar.After about 5 minutes, collect the chewed gum in the massed cup and wash your hands.Determine the mass of the cup and gum. Record it in your data table.Calculate the mass of sugar dissolved from the gum (original mass of gum – final mass of gum). Record the answer in your data table.Calculate the percentage of sugar in the gum by dividing the mass of the dissolved sugar by the mass of the un-chewed gum and multiply by 100. Record the answer in your data table.Data: Mass of Paper Cup (g)Mass of Cup + Gum(g)Mass of Un-Chewed Gum(g)Mass of Cup + Chewed Gum(g)Mass of Chewed Gum(g)Mass of sugar(g)% SugarAnalysis/Conclusions:What percent of the total mass of the gum is sugar? (Show calculations below.) _________________What is the molar mass of the sugar, C12H22O11? (Show your work below.) _____________________Convert the mass of dissolved sugar to moles. (Show your work below.) _______________________How many molecules of sugar are in the dissolved sugar? (Show your work below.) _______________MolesUnit 4Mole Unit Experiment:Problem/ Given Information: You wake up early to go help your friend build a shed on the side of their house. You get to the house and discover that they have already built the whole structure and just need to shingle the roof. Your friend asks you to go to the local home improvement store and buy some roofing nails before you start the job. You get to the local home improvement store and ask the friendly helper for the location of the nails. The helper brings you to them. Upon seeing all of the kinds of nails to choose from you ask her, the home improvement helper, what makes these roofing nails so special. She states that the roofing nails have a zinc coating around the actual iron nail making the nails much less likely to oxidize or rust, which helps keep the shingles on the roof for a long time. You thank the helper and buy your nails. You finish out the day helping your friend shingle the roof.On your way home you find a nail in your pocket and decide that you want to know the ratio, in moles, between the zinc and iron of the nail. Plan a procedure to do just that.Other pertinent information: 4972050508000Hydrochloric Acid reacts with zinc, however not with the iron.229616015748000The inner core of the nail is iron and the outer coating is the zinc.1392865143732003118485-127000Equipment:Everything in the Lab DrawersBalanceNailHydrochloric Acid27432004471035002743200447103500Procedure:MolesUnit 4Data: (Remember to include both qualitative and quantitative data)Calculations: (Remember to show formulas and include units!)Moles of Zinc CoatingMoles of Iron CoreMole Ratio of Fe to ZnCalculate the number of zinc atoms in the coatingMolesUnit 4Activity: The Strange Case of Mole Airlines Flight 1023You and your CSI team are called to the scene of a plane crash. The plane shows evidence of a pre-crash explosion. The site of the explosion has a compound with the following analysis: 37.01% carbon, 2.22% hydrogen, 18.5% nitrogen, and 42.27% oxygen. The victims are found in around the crash and must be identified by the substance found in their belongings or in their bodies since dental records are not available. Further evidence reveals that one person was murdered with the time of death established as one hour before the crash.Your job is to:Use the percent composition data to determine the empirical formulas and identities for the compounds found at the crash site. (You must show all work!)Use the percent composition data in Table 1 to determine formulas for the compounds found with or in the passengers. Be certain to use the number of significant figures in the analysis to determine the number of significant figures you need to use from the periodic table. Write these formulas in Table 3. Show all your work for figuring out these formulas!!.Match these formulas with the identity of each compound listed in Table 2. Write out the identity of each compound in Table 4.Use the personal data in Table 3 to make a probable identification of each passenger. Record the identifications in Table 5: Victim Identification Form. The solution to the puzzle is in every case that the evidence points to by logical deduction. Be sure to include the evidence that you think supports your deduction. Compare your answers with others. Do you agree?Table 1: Compound Analysis and where it was foundVICTIM #ANALYSIS OF COMPOUNDWHERE FOUND% C% H% N% O1.67.316.984.6221.10blood & luggage2.63.1546.665.304.480.031.131.5517.76briefcase (a)stomach (b)3.72.157.084.6816.03pockets4.15.872.2218.5163.41blood & pockets5.75.4237.016.632.228.3818.59.5742.27blood (a)luggage (b)6.57.146.169.5227.18stomach7.80.4881.587.458.909.399.522.680.0briefcase (a)luggage (b)8.60.0063.564.486.000.09.2735.5321.17pocket & briefcase(a)pocket & briefcase(b)MolesUnit 4Table 2: Chemical Compounds, Identities, & FormulasPOSSIBLE COMPOUNDSNAMEFORMULANOTEScodeineC18H21NO3painkiller, prescription, controlledcocaineC17H21NO4narcotic, illegalaspirinC9H8O4pain killervanillaC8H8O3flavoringtrinitrotolueneC7H5N3O6explosivenitroglycerineC3H5N3O9explosive, heart medicationcurareC40H44N4OpoisonthiobromineC7H8N4O2chocolate (flavoring)strychnineC21H22N2O2rat poisondimetacrineC10H13Nantidepressant, prescriptionacetaminophenC8H9NO2pain killer (Tylenol)aspartameC14H18N2O5artificial sweetener (NutraSweet)Table 3: The Flight List of Passengers & CrewNAMENOTESAmadeo OldereThe pilot, has a heart conditionConnie MajorsPharmacistJim LeClaireBakerArchie StarrTeacher addicted to sugar free drinksBob (Reno) HendersonPro athlete suspended for drug violationsLisa JoEnvironmental engineer, severely depressedBill (Cadillac) JacksonSuspected drug dealerNorm AndersonSuspected leader of a terrorist organizationMolesUnit 4Table 4: % Composition Data PassengerCompound Analysis (%)LocationEmpirical Formula & Name of SubstanceCHNO167.316.984.6221.10Blood & Luggage263.155.30--31.55Briefcase (a)46.664.4831.117.76Stomach (b)372.157.084.6816.03Pockets (2000 tablets)415.872.2218.5163.41Blood & Pockets575.426.638.38 9.57Blood (a)37.012.22 18.542.27Luggage (b)657.146.169.5227.18Stomach780.487.459.39 2.68Briefcase (a)81.588.909.52--Luggage (b)860.004.48--35.53Pocket & Briefcase (a)63.566.009.2721.17Pocket & Briefcase (b)MolesUnit 4Table 5: Victim Identification FormPassenger Most Probable IdentityEvidence that Supports Identification12345678___________________________ was murdered by ____________________Identity of Substance at the site of the explosion: ____________________________Certified by _____________________________ Date __________________What was the chemical at the crash site?Who was the murderer? Who was the murder victim?Who blew up the plane?MolesUnit 4Calculations Work Space:#CHNOFormula12a2b345a5b67a7b8a8bMolesUnit 4Lab: Formula of a HydrateIntroduction:Many compounds that have been crystallized from water solutions appear to be perfectly dry, yet when heated yield large quantities of water. The crystals change form, and sometimes color, as the water is driven off. This suggests that water was present as part of the crystal structure. Such compounds are called hydrates. A hydrate that has lost its water is called an anhydrous salt. For a hydrate, the number of moles of water present per mole of salt is usually some simple, whole number. A hydrate – which consists of an anhydrous salt and water – is often symbolized MN . ? H2O, where the M represents the “metal”, the N represents the “nonmetal” and the question mark indicates the number of water molecules for each formula unit of salt. One example of a hydrate is copper (II) sulfate pentahydrate. Its blue crystals look and feel dry, but each mole of the anhydrous salt is actually bonded to five moles of water. The compound’s formula is CuSO4 . 5 H2O. The molar mass of CuSO4 . 5 H2O can be found according to the following calculation:63.5 g + 32.1 g + 4 (16.0 g) + [ 5 (18.0 g) ] = 249.6 gIf a 249.6 g sample of CuSO4 . 5 H2O were heated to drive off all the water, the anhydrous salt CuSO4 would weigh 63.5 g + 32.1 g + 4 (16.0 g) = 159.6 g, which is the mass of one mole of CuSO4. The mass of water that has been boiled off into the air is [5 (18.0 g)] = 90.0 g, which is the mass of five moles of water. The formula of the hydrate shows the ratio of the moles of anhydrous salt to the moles of water; in the above case, that ratio is 1:5. Purpose: In this experiment, you will be given a sample of hydrate. You will determine the mass of the water driven off by heating, as well as the amount of anhydrous salt that remains behind. Then, given the mass of one mole of the anhydrous salt, you will determine the empirical formula of the hydrate. Pre-Lab Questions:Use the information to answer the questions. Show work, include units, and put your answers in the blanks.William weighs an empty crucible with its cover and finds it to have a mass of 95.83 g. After putting a spoonful of an unknown hydrate into the crucible, he finds that the mass has increased slightly to 99.87 g. He heats the crucible and its contents, and finds that the mass has dropped to 97.22 g. William is told by his teacher that the molar mass of the anhydrous salt is 74.10 g.1. What mass of hydrate did William start with? ________________________2. How much water was driven off from the hydrate during the heating process in units of ….A) grams _________________B) moles __________________3. How much anhydrous salt remained in the crucible in units of….A) grams _________________B) moles ___________________4. Write down the mole ratio as whole numbers: ______ moles anhydrous salt : ______ moles water5. What is the formula of the hydrate? (use MN to symbolize the anhydrous salt): _____ MN ? ____ H2O6. Based on William’s data, calculate the percentage of water in the sample of hydrate. MolesUnit 4543306022352000Materials:balance Bunsen burnercrucible crucible tongsring stand and ringclay trianglematchessample of hydrateProcedure:1. Mass a clean dry crucible with cover and record in the data table.2. Put enough hydrate in the crucible to fill it about 1/3 of the way full.3. Observe and record the color and texture of the substance. 4. Take the mass of the crucible, cover, and the hydrate and record.5. Place the crucible with hydrate and cover on the triangle (as shown above in Figure 1) and heat to RED HOT for 5 minutes. The bottom of the crucible should be a dull red during this entire time. Allow the crucible to COOL for 5 minutes and do NOT remove the cover. DO NOT TOUCH!!!6. When the crucible is cool enough to touch, transfer it and the cover to the balance, mass, and record.7. Observe and record the color and the texture of the ANHYDRATE. Data Table: (record all quantities to the nearest 0.01 g)Quantity MeasuredMass(g)ObservationsDry crucible and coverCrucible, cover, and contents before heatingCrucible, cover, and contents after heatingMolar mass of anhydrous salt (given)159.62 g/molPercentage of water in hydrate (given)36.10%Data Analysis/Calculations: Show your work, include units, and write your answers in the blanks.What mass of hydrate did you start with? ____________________How much water was driven off from the hydrate in the units of Grams ________________B) Moles ______________________How much anhydrous salt remained in the units of Grams _________________B) Moles _____________________MolesUnit 4Write down the mole ratio as decimal numbers. _____________Moles of Anhydrous Salt : ________________ Moles of H2OWrite down the mole ratio as whole numbers____________ Moles of Anhydrous Salt : _________________ Moles H2OWhat was the formula of your hydrate? ________________________Based on your data, calculate the percentage of water in the sample of hydrate.__________________Calculate the percent error in your experiment by comparing the actual percentage of water with the percentage you obtained in your experiment. MolesUnit 4Unit Reflection:Using 5 of the learning objectives listed in the front of the Lab Manual, show how the lab/activity exemplifies that objectiveLearning Objective #Lab:Candy MolesLab: What does a Mole Look LikeLab: Isn’t Chemistry SweetLab: % Sugar in Bubble GumLab: Mole Unit ExperimentLab: Mole AirlineLab: Formula of a Hydrate12345Compare and contrast the purpose and outcome of 2 labs, using a minimum of 3 examples. MolesUnit 4Using one lab as an example, explain how you would modify/expand the procedure to test a new aspect of the learning objectives. Defend your answer.Give one laboratory and one real life application of the techniques learnt in this lab book. MolesUnit 4Article:Title: Summary:Discussion:Individual:Group:MolesUnit 4Questions:Generate and answer a Costas level 1, 2 and 3 test question based on the labs and learning objectives of this unit. MolesUnit 4MolesUnit 4Personal Choice: STAPLE YOUR MOLE ISLAND TO THIS SHEET ................
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