Honors Chemistry
Lab Manual
Unit 4
Moles
Moles Unit 4
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Moles Unit 4
Upon Completion of the labs and activities within this unit you will be able to…
1. Perform one step molar conversions
(mass↔moles, particles↔moles, L↔moles)
2. Perform multi-step molar conversions
(particles↔mass, L↔particles, L↔mass)
3. Determine the % composition of various compounds
4. Calculate the empirical and molecular formulas for various compounds (including
hydrates)
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Moles Unit 4
Lab: Candy Moles
Yummy 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 pieces
The 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:
Brand
Size (approx.)
Mass (g) of 1 Mmmmmmmmmm
Gummy Candy
M & M’s
Starbursts
Procedure:
1.
2.
3.
4.
Transfer 1 Mmmmmmmmmm of each candy into its own container (Dixie® cup)
Use the empty cup by the balance to zero out the balance
Place your cup with 1 Mmmmmmmmmm of candy in it on the balance & record the mass
Repeat for each type of candy
Analysis Questions:
You must show your work for all calculations or lab will be given ZERO credit!
1. Which type of candy had the greatest mass per 1 Mmmmmmmmmm? The least? Why does this make
sense?
2. 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.?)
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Moles Unit 4
3. If each individual candy is a particle, how many particles are present per unit (1 Mmmmmmmmmm) of
the above chemical measurement?
4. How many grams of M&Ms would be in 3.5 Mmmmmmmmmm’s? (Show your work!)
5. If you eat 6.3 g of Starbursts, how many servings have you had (remember: the serving size = 1
Mmmmmmmmmm)
6. My student Cindy is a big fan of gum drops, the other day she ate 53, how many grams was that?
7. How do you think this lab relates to how scientists use the mole? (Write at least four well thought
out, complete sentences  )
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Moles Unit 4
Lab - 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.
PROCEDURE
1. Fill 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 Description
Actual Measurement (watch sig. figs.!)
A
Mass of water
g
B
Mass of water after drinking one sip
g
C
Mass of water consumed
g
D
Moles of water consumed (show work below)
mols
E
Molecules of water consumed (show work below)
m’c
2. Obtain 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 Description
Actual Measurement (watch sig. figs.!)
A
Mass of chalk
g
B
Mass of chalk after writing message
g
C
Mass of chalk consumed
g
D
Moles of chalk consumed (show work below)
mols
E
Molecules of chalk consumed (show work below)
m’c
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Moles Unit 4
How 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/cm 3, and compute the thickness of your
piece of foil.
3. 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/cm 3.
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 Description
A
Actual Measurement (watch sig. figs.!)
Length of Al foil
cm
Width of Al foil
cm
B
Density of Al
C
Mass of Al foil
D
Volume of Al foil (show work below)
g/cm3
g
cm3
E
Height of Al foil (show work below)
cm
F
G
Atoms thick of Al foil (thickness of 1 Al atom = 2.5 x 10-8 cm: show
work below)
atoms
Moles in Al foil (show work below)
mols
H
Atoms in Al foil ( show work below)
atoms
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Moles Unit 4
QUESTIONS – Answer in complete sentences!!
1. Identify the conversion factors you used and specify how you used them.
2. 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.
3. 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.
4. 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?
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Moles Unit 4
Lab – Isn’t Chemistry Sweet !!
Supplies:
Sugar (sucrose C12H22O11)
Disposable Beaker (plastic cup)
Disposable Scoopulas (spoons)
Chemistry Flavor Crystals
Procedure:
1.
2.
3.
4.
5.
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…
1. What units did I give you to use when measuring out sucrose?
2. Can you use our balances to measure this amount as is?
3. What do you need to convert the original unit to?
4. How will you do this (set up the correct dimensional analysis to go from moles of sucrose- C12H22O11 to
grams)
5. How many grams of sucrose will you need to mass out (answer to calculating set up of #4)?
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Moles Unit 4
Lab: Percent Sugar in Bubble Gum
Problem: What percent of bubble gum is sugar?
Materials:
 5 pieces of sugared bubble gum
 paper cup
 balance
Procedure:
1.
2.
3.
4.
5.
6.
7.
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.
8. 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)
% Sugar
Analysis/Conclusions:
1. What percent of the total mass of the gum is sugar? (Show calculations below.) _________________
2. What is the molar mass of the sugar, C12H22O11? (Show your work below.) _____________________
3. Convert the mass of dissolved sugar to moles. (Show your work below.) _______________________
4. How many molecules of sugar are in the dissolved sugar? (Show your work below.) _______________
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Moles Unit 4
Mole 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:
Hydrochloric Acid reacts with zinc, however not with the iron.
The inner core of the nail is iron and the outer coating is the zinc.
Equipment:
Everything in the Lab Drawers
Balance
Nail
Hydrochloric Acid
Procedure:
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Moles Unit 4
Data: (Remember to include both qualitative and quantitative data)
Calculations: (Remember to show formulas and include units!)
1) Moles of Zinc Coating
2) Moles of Iron Core
3) Mole Ratio of Fe to Zn
4) Calculate the number of zinc atoms in the coating
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Moles Unit 4
Activity: The Strange Case of Mole Airlines Flight 1023
You 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!)
1. 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!!.
2. Match these formulas with the identity of each compound listed in Table 2. Write out the identity of each compound in
Table 4.
3. 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.
4. Compare your answers with others. Do you agree?
Table 1: Compound Analysis and where it was found
ANALYSIS OF COMPOUND
WHERE FOUND
VICTIM #
%C
%H
%N
%O
1.
67.31
6.98
4.62
21.10
blood & luggage
2.
63.15
5.30
0.0
31.55
briefcase (a)
46.66
4.48
31.1
17.76
stomach (b)
3.
72.15
7.08
4.68
16.03
pockets
4.
15.87
2.22
18.51
63.41
blood & pockets
5.
75.42
6.63
8.38
9.57
blood (a)
37.01
2.22
18.5
42.27
luggage (b)
6.
57.14
6.16
9.52
27.18
stomach
7.
80.48
7.45
9.39
2.68
briefcase (a)
81.58
8.90
9.52
0.0
luggage (b)
60.00
4.48
0.0
35.53
pocket & briefcase(a)
63.56
6.00
9.27
21.17
pocket & briefcase(b)
8.
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Moles Unit 4
Table 2: Chemical Compounds, Identities, & Formulas
POSSIBLE COMPOUNDS
NAME
FORMULA
NOTES
codeine
C18H21NO3
painkiller, prescription, controlled
cocaine
C17H21NO4
narcotic, illegal
aspirin
C9H8O4
pain killer
vanilla
C8H8O3
flavoring
trinitrotoluene
C7H5N3O6
explosive
nitroglycerine
C3H5N3O9
explosive, heart medication
curare
C40H44N4O
poison
thiobromine
C7H8N4O2
chocolate (flavoring)
strychnine
C21H22N2O2
rat poison
dimetacrine
C10H13N
antidepressant, prescription
acetaminophen
C8H9NO2
pain killer (Tylenol)
aspartame
C14H18N2O5
artificial sweetener (NutraSweet)
Table 3: The Flight List of Passengers & Crew
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NAME
NOTES
Amadeo Oldere
The pilot, has a heart condition
Connie Majors
Pharmacist
Jim LeClaire
Baker
Archie Starr
Teacher addicted to sugar free drinks
Bob (Reno) Henderson
Pro athlete suspended for drug violations
Lisa Jo
Environmental engineer, severely depressed
Bill (Cadillac) Jackson
Suspected drug dealer
Norm Anderson
Suspected leader of a terrorist organization
Moles Unit 4
Table 4: % Composition Data
Compound Analysis (%)
Passenger
1
Location
C
H
N
O
67.31
6.98
4.62
21.10
Blood &
Luggage
63.15
5.30
--
31.55
Briefcase (a)
2
Stomach (b)
46.66
4.48
31.1
17.76
3
72.15
7.08
4.68
16.03
Pockets
(2000 tablets)
4
15.87
2.22
18.51
63.41
Blood &
Pockets
75.42
6.63
8.38
9.57
Blood (a)
37.01
2.22
18.5
42.27
Luggage (b)
57.14
6.16
9.52
27.18
Stomach
80.48
7.45
9.39
2.68
Briefcase (a)
81.58
8.90
9.52
--
Luggage (b)
60.00
4.48
--
35.53
Pocket &
Briefcase (a)
63.56
6.00
9.27
21.17
Pocket &
Briefcase (b)
5
6
7
8
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Empirical Formula & Name of Substance
Moles Unit 4
Table 5: Victim Identification Form
Passenger
Most Probable Identity
Evidence that Supports
Identification
1
2
3
4
5
6
7
8
___________________________ was murdered by ____________________
Identity of Substance at the site of the explosion:
____________________________
Certified by _____________________________ Date __________________
1. What was the chemical at the crash site?
2. Who was the murderer? Who was the murder victim?
3. Who blew up the plane?
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Moles Unit 4
Calculations Work Space:
#
1
2a
2b
3
4
5a
5b
6
7a
7b
8a
8b
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C
H
N
O
Formula
Moles Unit 4
Lab: Formula of a Hydrate
Introduction:
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 g
If a 249.6 g sample of CuSO4 . 5 H2O were heated to drive off all the water, the anhydrous salt CuSO 4 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 _________________
4. Write down the mole ratio as whole numbers:
B) moles ___________________
______ moles anhydrous salt : ______ moles water
5. What is the formula of the hydrate? (use MN to symbolize the anhydrous salt): _____ MN ∙ ____ H2O
6. Based on William’s data, calculate the percentage of water in the sample of hydrate.
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Moles Unit 4
Materials:
balance
Bunsen burner
crucible
crucible tongs
ring stand and ring
clay triangle
matches
sample of hydrate
Procedure:
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 Measured
Mass(g)
Observations
Dry crucible and cover
Crucible, cover, and contents before heating
Crucible, cover, and contents after heating
Molar mass of anhydrous salt (given)
159.62 g/mol
Percentage of water in hydrate (given)
36.10%
Data Analysis/Calculations: Show your work, include units, and write your answers in the blanks.
1) What mass of hydrate did you start with? ____________________
2) How much water was driven off from the hydrate in the units of
A) Grams ________________
B) Moles ______________________
3) How much anhydrous salt remained in the units of
A) Grams _________________
B) Moles _____________________
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Moles Unit 4
4) Write down the mole ratio as decimal numbers.
_____________Moles of Anhydrous Salt : ________________ Moles of H2O
5) Write down the mole ratio as whole numbers
____________ Moles of Anhydrous Salt : _________________ Moles H2O
6) What was the formula of your hydrate?
________________________
7) Based on your data, calculate the percentage of water in the sample of hydrate.__________________
8) Calculate the percent error in your experiment by comparing the actual percentage of water with the
percentage you obtained in your experiment.
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Moles Unit 4
Unit Reflection:
1. Using 5 of the learning objectives listed in the front of the Lab Manual, show how the lab/activity
exemplifies that objective
Learning
Objective
#
Lab:
Candy
Moles
Lab: What
does a
Mole Look
Like
Lab: Isn’t
Chemistry
Sweet
Lab: %
Sugar in
Bubble
Gum
Lab: Mole
Lab: Mole
Unit
Airline
Experiment
Lab:
Formula of
a Hydrate
1
2
3
4
5
2. Compare and contrast the purpose and outcome of 2 labs, using a minimum of 3 examples.
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Moles Unit 4
3. Using 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.
4. Give one laboratory and one real life application of the techniques learnt in this lab book.
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Moles Unit 4
Article:
Title:
Summary:
Discussion:
Individual:
Group:
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Moles Unit 4
Questions:
Generate and answer a Costas level 1, 2 and 3 test question based on the labs and learning objectives
of this unit.
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Moles Unit 4
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Moles Unit 4
Personal Choice:
STAPLE YOUR MOLE ISLAND TO THIS SHEET
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