Unit 3 Packet - Page 1 of 15Chemistry - Unit 3 The moleVocab Assignment Due: Pre-Lab Due:PS/BQs Due: Test Date: Mole mini project:

VOCABULARY1 molecular mass 2 formula mass 3 hydrate 4 Avogadro’s number 5 mole 6Molarity 7 percent composition 8 empirical formula 9 molecular formula 10 formula unit 11 ionic compound 12 molecular compound

FORMULA/CONSTANTS Molar mass conversionMolar volume conversions *Avogadro’s number *Molarity

OBJECTIVES: Be able to perform math functions using correct scientific notation. Be able to find molecular/formula mass using the periodic table. Be able to calculate Molarity. Be able to calculate percent composition. Be able to use molar volume in problems Be able to determine empirical and molecular formulas using lab data.

Percent to mass; mass to mole; divide by small; multiply to whole! Understand the mole and Avogadro’s number. Be able to convert to/from atoms, ions, molecules, moles, liters and grams.

BQS: Review Questions:1. Name the following compounds:

A. Ba(C2H3O2)2 C. Sn(NO2)2B. P3S2 D. Na2O

2. Write the formulas for A. potassium sulfate B. lead (II) nitride C. carbon dioxide

Current Unit Material:3. Find the molar mass of the following A. BaCl2 B. Cu(NO2)2 C. aluminum sulfide

4. Given 35.1 g of Carbon dioxide gas convert toA. Moles B. molecules C. liters (at STP)

5. A. Write the formula for calcium sulfate. B. What is the percentage of sulfur in calcium sulfate?

6. Calculate the empirical formula of a compound that contains 1.67 g of Cerium, Ce and 4.54 g of iodine, I .

7. What is the molarity of 4.32 g of lithium sulfide in 200 ml of solution?

8 Extra Credit. If you are driving 55 miles per hour, how many minutes will it take to travel 25 km?

Guided Note-Taking for THE MOLE!What is a mole?

Unit 3 Packet - Page 2 of 15 “Official Definition”

the amount of a substance that contains as many particles as there are atoms in exactly 12g of carbon-12

A mole is a counting unit just like a dozen other examples…..

Avogadro’s Number Constant the number of particles in exactly one mole of a pure substance

1 mol = 6.02 X1023 of anythingBut most often the mole is used with atoms, ions, formula units or moleculesExamples of Conversion Factors: 1 mol 1 mol 6.02 X 1023 molecules 6.02 X 1023 atoms, ions

or formula units Molar MassMass in g of 1 mole of anything

For an element, the molar mass is equal to the atomic weight from the periodic table.

1 mol atomic wt. (g)Molar Mass Examples: 1 mol C and 1 mol I

12.0 g C 126.9 g IYou try: 1 mol Ca 1 mol Fe ____ g Ca _____ g Fe

Now, you have two conversion Factors for a mole…..Avogadro’s number Molar mass1 mol and 1 mol6.02 X 1023 atoms, ions, formula units, or molecules ? g

Example 1 How many g in 2.0 mol of He?

Example 2 How many moles in 3.01 X 1023 atoms Ag?

Example 3 What is the mass of 1.20 X 1021 atoms of Cu??

You try: A. Convert 21.5 g B to moles B

B. Convert 8.0 X 1021 atoms of Ag to gFormula Mass/Molecular Mass/Molar Mass = Sum of masses in a compoundExample: Molar Mass of K2SO4

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Example: molar mass of Li2S ∙ 3 H2O

You try: Molar Mass of Ca(NO3)2

These can be used as conversion factors!1 mol MgCl2 95.21g MgCl2

Example: How many mol in 127g barium chloride?

You try: How many molecules in 32 g of nitrogen dioxide

Notes on Molar volume:At STP (standard temperature and pressure = 1 atm and 273 K), one mole of any gas has a volume of 22.4 L. This is called molar volume and can be used as a conversion factor. 1mol gas or 22.4 L22.4 L 1 mol gas

example problem: Convert 5.0 moles of Hydrogen gas (H2) to L.

Example two: Convert 2.2 L of ammonia gas NH3 to g.

You try: 1. Convert 1.6 moles of O2 gas to L.

2. Convert 5.0 g of Ozone, O3 to liters.

Guided Note-Taking on Percent CompositionPercent composition is the percent by mass of each element in a compound.Percent composition is the same, regardless of the size of the sample.

Percent Composition Calculations% comp = mass of element X 100% = % element in the compound

molar mass of cmpd

Example: Find the % composition of Cu2S1. find the molar mass 2. Next, find the % of each element 3. Next, check your work – do the %s add up to 100?

Unit 3 Packet - Page 4 of 15Example 2 : find the percent of water in Li2S ∙ 3 H2O

You try: 1) barium chloride

2) sodium phosphate

3) perecent water in CuCl2 •5 H2O

Guided Note-Taking on Empirical FormulasEmpirical Formula = Simplest Formula

To find the empirical formula from data:1. Assume 100% sample; change % to grams for each element2. Find moles from the grams of each element3. Find the smallest whole # ratio by dividing by the smallest number of moles4. If necessary, multiply to get rid of fractions.A little rhyme to help you remember the steps:

Percent to mass Mass to mole Divide by small Multiply 'til whole Example 1: A compound is 78% B and 22% H. What is the empirical formula?

First, change % to grams and find moles:Next, divide all mole numbers by the smallest number of moles:Finally, use these whole numbers as the number of each individual element. They are the subscripts.

Example 2: a hydrate is composed of 19.2 % sodium, 13.3 % sulfur and 67.5 % water – find this compounds empirical formula

Example 3: Analysis shows a compound to contain 26.56% K, 35.41% Cr, and 38.03% O. Find the empirical formula of this compound:First (always!) assume 100g sample, convert % to g and then find moles of each element.Next, Conversion to moles:Next , divide all numbers by the smallest whole number to find the smallest whole number ratios:

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So, if you have: multiply all by:.25 or .75 4.33 or .66 3.50 2 (this is the only type we will do)

You Try: What is the empirical formula if we have a sample containing 66.0% Ca and 34.0% P?

You Try: Find the empirical formula of a compound with 32.38% Na; 22.65% S; and 44.99% O.

Practice:

Molecular Formula Molecular Formula = Actual FormulaExample: C2H6 CH3

molecular empiricalMF = (EF)x where X = Molecular mass

Empirical massExample: The empirical formula of a compound was found to be P2O5. Experimentation shows that the molar mass of this compound is 283.89 g/mol. What is the compound’s molecular formula?

You try: The empirical formula of a compound is CH6O – the molar mass of the compound is 180 – what is the molecular formula?

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Guided Note-Taking on Moles in Solution (Molarity)Molarity is the term used for moles dissolved in solutionSymbol for Molarity = MDefinition – moles of solute per liter of solutionFormula M = moles solute (mol) in ref packet

liter solution (L)

Example 1: What is the molarity of a 0.5L solution containing 2 moles of NaCl?

Example 2: What is the molarity of a 250 mL solution containing 12.7 g of lithium bromide?

You try: 1) Calculate the M of a 700. mL solution of 23.2g calcium chloride

Unit 3 Packet - Page 7 of 152) What is the molarity of a 0.25 L solution containing 0.55 moles of potassium nitrate?

CONVERSION WORKSHEET NAME:____________________________A. Convert the following: 1. 1.20 x 1025 atoms of N to moles

2. 11.5 g of carbon to moles

3. 1.00 x 1024 atoms of Thallium (Tl) to grams

4. 3.01 x 10 23 atoms of Mg to moles

5. 2.1 g of Ni to atoms

6. 0.400 moles of Cd(IO3)2 to formula units

7. 76.0 g of Ca to moles

8. 46.0 g of potassium nitride to formula units

9. 1.00 x 1023 formula units of CsBr to grams

10. 3.00 liters of Cl2 to grams

11. 9.30 moles of carbon dioxide to liters

12. 8.00 x 1019 formula units of copper (II) sulfate to grams

13. 34.2 g of trisulfur dioxide gas to liters

B. Molarity Practice 14. What is the molarity of the following?

a. 5.23 g Fe(NO3)2 in 100 ml of solution.

b. 8.55 g of ammonium iodide in 0.5 L of solution.

c. 32 g of cobalt (II) sulfate in 4.3 L of solution.Composition of Hydrates Practice sheet:

1. What percentage of water is found in CuSO4•5 H2O?

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2. What percentage of water is found in Na2S •9H2O?

3. A 5.0 g sample of a hydrate of Ca(NO3)2 was heated, and only 1.7 g of the anhydrous salt remained. What percentage of water was in the hydrate?

4. A 5.0 g sample of Cu(NO3)2 •n H2O is heated and 3.9 g of the anhydrous salt remains. What is the value of n?

Chapter Seven– Practice Sheet Empirical, Molecular, and Molarity1. Analysis of a sample of sulfuric acid shows it to contain 0.17 g of hydrogen, 2.82

g of sulfur, and 5.67 g of oxygen. What is the empirical formula for this compound?

2. Analysis of a salt results in the following composition: 3.47 g of Na, 2.12 g of N and 7.27 g of oxygen. What is the simplest formula of this salt?

3. A barium salt is found to contain 21.93 g of barium, 5.12 g of sulfur and 10.24 g of O. What is the empirical formula?

4. A compound contains: 26.7 % C, 2.2 % H and 71.1 % O. The molecular weight of the compound is 90. What is the compound’s molecular formula?

5. A certain compound contains only C, H, and O. If 54.6 % is C and 9.0 % is H and the molecular weight is 176, what are the compounds empirical and molecular formulas?

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6. The percentage composition of ethane gas is 80.0 % C and 20.0 % H. The molecular weight for ethane is 30. What is the molecular formula for this compound?

7. What is the M of 32.3 g of calcium chloride in 750 ml of solution?

REVIEW – Chemistry Unit Three1. How many liters are present in 115 g of nitrogen dioxide?

2. How many molecules in 0.943 moles of water?

3. How many formula units in 64.3 g of lithium sulfate?

4. What is the molarity of 9.94 g of cobalt (II) sulfate in 250. ml of solution?

5. How many moles of platinum are equivalent to 1.20 x 1024 atoms?

6. What is the percentage of nitrogen in urea, CO(NH2)2?

7. A compound contains 27.3 g of C and 72.7 g of O. What is the empirical formula for this compound?

8. A compound is 13 % Mg and 87 % Br - What is the compound’s empirical formula?

9. A compound with a formula mass of 34 is found to consist of 0.44 g of H and 6.92 g of O. Find its empirical formula and molecular formula

Chemistry Enrichment Activity Mole Day Due Date: Oct 15th

National Mole Day begins at 6:02 a.m. on 10/23 and ends on the same day at 6:02 p.m. This is significant since 1 mole of anything is 6.02 x 1023 things (just like 1 dozen = 12 things). The following activities are intended to show that chemistry can be fun!You may complete as many of the activities you wish, adding up to a total point value of 10 pts (or more – if you go over 10 pts you will not receive extra credit but your grade will be based on 20 possible points) Do all work on your own paper!

Unit 3 Packet - Page 10 of 151. Write a paragraph answering the questions: Who was Amedo Avogadro? What was his hypothesis? (5 pts)

2. Make a .5 mole aluminum foil sculpture of a mole (the critter). The sculpture will be checked and weighed for the grade. You may come in the mornings to use an electronic balance if necessary! (5 pts)

3. Solve 2 of the following mole problems. All work must be presented neatly. (3 pts each for a total of 6 pts) A. If you spend a million dollars a day, how many years would it take to spend one mole of dollars? B. How many pencil marks can you make in one minute – how long would it take you to make 1 mole of marks? C. Usain Bolt holds the world record for the 100 meter dash – 9.58 seconds – how long would it take Mr. Bolt to run a mole of meters (assuming he keeps this pace)

4.     Use a mole pattern (see Mrs. Haywood) and create a stuffed mole. Turn in completed mole. Sorry, the mole will not be returned. (17 pts)

5.    Write an original mole joke. Put it on a separate paper so it can be displayed! 3 examples follow: (2 pts) What is chemical nonsense? Mole-arky What does Avogardro wear when it is cold? Thermole Underware Where did Avogardro stay on vacation? A Mole-tel

6.    Consume 1 mole of water in Mrs. Haywood’s presence (during a help session). Bring the water pre-measured in your own container! (5 pt) 

7.  Make a poster promoting Mole Day, October 23, to be placed around the school. Include this year’s theme – Molar Eclipse (10 pts) 

8.  Make a Mole Day greeting card (to be sent to other chemistry students) include this years theme! (5 pts)

9. Wear a Mole day costume to class on Mole day (5 pts)

10. Make a Mole-bile – to be Hung from the ceiling. (5 pts)

11. Write a Mole Day poem (at least 3 “lines”); may be any type of poem including a haiku (5 pts)

12. Write a mole day story (at least 2 paragraphs) (5pts)

13. Write a mole day cartoon (5 pts)

14. Make a Mole Day flag – it may be on cloth or paper (5 pts)

15. Make Mole Day treats (enough for the class – see Mrs. Haywood to sign up for a day to bring the treats in!): exs: Moleasses cookies, Avogadro Dip, or Taco-mole sauce (5pts)

16. Mole Day Web page – make a web page for mole day –see Mrs. H for points – up to 20 pts depending on the web page design!

17. Make a Mole day playlist for Avogadro’s Ipod – should include at least 8 songs with title and artist (5pts) You MUST attach the completed grade rubric with your project!!! RUBRIC AT THE END OF PACKET!

Lab on Percent composition & Hydrates Name:Partners:Date:Station

Unit 3 Packet - Page 11 of 15Objective: You will study both hydrates and percent composition through proper lab techniques. Using data gathered during the lab, you will calculate the percent of water in a hydrate.

Equipment: For your pre-lab assignment make a list of the equipment you will be using.

Procedure:Finding the percentage of water in copper (II) sulfate that is hydrated.

1. Determine and record the mass of an empty evaporating dish using the balance.2. Get about 2 - 5g of copper (II) sulfate from Mrs. H. You will subtract to find the exact mass.3. Place the sample in the evaporating dish. Determine and record the mass of the evaporating

dish and sample.4. Place the evaporating dish on a hot plate.5. Heat the evaporating dish w/ the sample using a hot plate.6. Continue heating until the sample turns entirely white.7. Using tongs remove the dish from the hot plate.8. Turn off the hot plate and allow the sample to cool for 3 - 5 minutes.9. Determine and record the mass of the anhydrous sample and dish.10. Add a few drops of water to the cooled sample and note observations.11. Clean up by disposing of the sample in the trash – rinse out the dish and wipe it dry.

Data Table: Mass of evaporating dish _______________

Mass of evaporating dish and copper (II) sulfate ______________

*Mass of copper (II) sulfate used (before heating) ________________

Mass of evaporating dish and copper (II) sulfate (after heating) ______________

*Mass of anhydrous copper (II) sulfate (after heating)___________________________

* These masses are not measured during lab they will be calculated after completing the lab.

Calculations1. Calculate the mass of copper (II) sulfate used in the lab (before heating). Write this mass on your data table.

2. Calculate the mass of anhydrous copper (II) sulfate after heating. Write this mass on your data table.

3. Subtract the mass of the copper (II) sulfate hydrate after heating from the mass of the hydrate before heating to find the mass of water in your hydrate sample.

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4. Calculate the % of water in the Copper (II) sulfate when hydrated. Hint: this will involve the mass of water you found above and the mass of the hydrate before it was heated.

5. Calculate the % of copper (II) sulfate (before heating the sample).

6. Using the answers from 4 and 5 determine the formula for the copper (II) sulfate hydrate – ie how many waters will the formula contain. Hint look at the example on page 4/5 of this packet. SHOW WORK

Fill in the # of water molecules in the final formula here: CuSO4 ● _____ H2O

Write the name of your final compound here: ______________________________

Questions1. Was the copper (II) sulfate change, physical or chemical? why?

2. Why did we add water to the white copper (II) sulfate at the end of the experiment?

Conclusion: In this lab we studied percent composition as related to a hydrate. The definition of a hydrate is :_______________________________________________________________________________.

The hydrate went from a blue color to white and then back to blue because:____________________________________________________________________________________________.

This lab was: _____________________________________________________________

Mini Lab Atoms, moles and grams Name:_______________________________

Procedure:1. Your group should choose three bags to do (and only 3 bags). You should fill in the first two rows of the data table for all the substances and then the 3 columns of the bags you choose.

Unit 3 Packet - Page 13 of 153. You will rotate (with your lab group) to the various stations, massing the plastic bags of chemicals to determine grams. You may use the electronic balances. 4. You will then calculate the moles and atoms. Show your work under the table!5. Be sure to pay attention to which substance you are working with and record it in the appropriate place on your table.6. Return the bags at the end of the lab. DO NOT OPEN THE BAGS ANYTIME DURING THE LAB!!! DATA TABLEMass of an empty bag: ____________ g

FormulaNaCl CuSO4 C12H22O11 BaCl2 Pb

Namesugar Iron(II)

chlorideMagnesium oxide

Sample mass w/bag

Mass of Bag

Mass of Sample

Moles of Sample

Molecules/atoms of sample

Show detailed work for all three bags below:Bag 1 name___________________

Bag 2 name___________________

Bag 3 name_________________The Strange Case of Empirical Airlines Flight 1023 Names: _________________________News Flash!!! A jet airliner has mysteriously crashed with no survivors. According to air traffic controllers, the flight was proceeding as usual. The plane left Reagan International Airport on schedule and was due to arrive at Los Angeles Airport at 6:02 p.m. However, the plane fell off the radar somewhere in the Avogadro Memorial Forest. You and your team of medical examiners have been called to the scene of the crash. The plane shows evidence of a pre-crash explosion. There is a bomb residue on many of the plane parts scattered over the crash area. The bomb residue has been analyzed with the following results: 37.01% carbon, 2.22% hydrogen, 18.5% nitrogen, and 42.27% oxygen. The victims are found in an around the crashed plane and must be identified by the substances found in their bodies since dental records are not available. Additionally, one passenger was murdered and the time of death has been established as one hour before the crash. Your job is to…

Unit 3 Packet - Page 14 of 151. Identify compounds found on the victims by using the data below to determine the empirical formulas of the

compounds.2. Identify the victims using personal data and the compounds found with them.3. Explain why the plane exploded and who most likely was responsible.4. Determine which person was murdered and who is the most likely murderer.

Chemical analysis submitted by Dr. I. M. KoolVictim # Analysis of Compound (%) Where found

1 C = 67.31 H = 6.96 N = 4.62 O = 21.10 Blood and Luggage2 C = 63.15 H = 5.30 O = 31.55

C = 46.66 H = 4.48 N = 31.10 O = 17.76BriefcaseStomach

3 C = 71.68 H = 6.94 N = 4.68 O = 16.03 Pockets4 C = 15.87 H = 2.20 N = 18.15 O = 63.10 Blood & pockets5 C = 75.42 H = 6.63 N = 8.38 O = 9.57

C = 37.01 H = 2.22 N = 18.50 O = 42.27Blood

Luggage6 C = 57.14 H = 6.16 N = 9.52 O = 27.18 Briefcase7 C = 81.50 H = 7.50 N = 9.39 O = 2.68

C = 81.58 H = 8.90 N = 9.52BriefcaseLuggage

8 C = 60.00 H = 4.48 O = 35.53C = 63.56 H = 6.00 N = 9.27 O = 21.17C = 75.42 H = 6.63 N = 8.38 O = 9.57

Pockets & BriefcasePockets & Briefcase

Briefcase

List of Passengers and Crew Amadeo Aviator – a pilot with a heart condition Curie Drugs – sales representative of Advil Company Bohr Diet – Chemistry teacher “addicted” to sugar-free drinks Kelvin Doughnut – beaker, specializes in pastries shaped like famous scientist Democritus “D” Victory – professional athlete suspended for drug violations Ruthy Ford-Recycle – electrical engineer, had been severely depressed lately due to canceled project Dalton Molar – high school student who recently underwent dental surgery Norm Einstein – leader of group called the Mighty Order of Lavoisier Enthusiast, a suspected terrorist organization

more commonly known as M.O.L.E. According to Mole-der and Skulley the group’s goal is to make everyone aware of the power of Chemistry.

List of substances and their common usesName Formula Common UseCodeine ……………………. C18H21NO3…………………..Prescription painkiller, often used in dentistryCocaine C17H21NO4 Narcotic, illegal substanceAspirin………………………C9H8O4……………………... Painkiller, over the counterAspartame C14H18N2O5 Artificial sweetenerVanilla……………………… C8H8O3………………………Flavoring, used in bakingTrinitrotoluene C7H5N3O6 TNT, explosiveNitroglycerine………………. C3H5N3O9…………………. Explosive and heart medicationCurare C40H44N4O PoisonThiobromine……………….. C7H8N4O2………………….. Chocolate flavoring used in frosting on pastriesStrychnine C21H22N2O2 Rat poisonDimetacrine………………… C10H13N*…………………… Antidepressant prescription, *empirical formulaAcetaminophen C8H9NO2 Tylenol, non-prescription painkiller

Answer Sheet (make sure to attach your work to this page) no more than 2 people working together!

Victim Name of Victim Empirical Formula Name of chemical Found in victim’s:(where found)

1

2

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3

4

5

6

7

8

1. Why did the plane explode and who is most likely responsible for the plane explosion _________________________?

2. Who was murdered? _______________________ How do you know?

3. Who is most likely the murderer? _______________________ How do you know?