Chemistry I Booklet Fall Semesterchemistrywithmanakul.weebly.com/uploads/8/0/3/2/80327912/... ·...
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Chemistry I Booklet
Fall Semester
Class: Ms. Manakul
Student Name: ____________________
Student Hour: _________
Periodic Table of the Elements
hydrogen
1
H 1.0079
helium
2
He 4.0026
lithium
3
Li 6.941
beryllium
4
Be 9.0122
boron
5
B 10.81
carbon
6
C 12.011
nitrogen
7
N 14.007
oxygen
8
O 15.999
fluorine
9
F 18.998
Neon
10
Ne 20.179
sodium
11
Na 22.990
magnesium
12
Mg 24.305
aluminium
13
Al 26.982
silicon
14
Si 28.086
phosphorus
15
P 30.974
sulphur
16
S 32.06
chlorine
17
Cl 35.453
argon
18
Ar 39.984
potassium
19
K 39.098
calcium
20
Ca 40.08
scandium
21
Sc 44.956
titanium
22
Ti 47.90
vanadium
23
V 50.941
chromium
24
Cr 51.996
manganese
25
Mn 54.938
iron
26
Fe 55.847
cobalt
27
Co 58.933
nickel
28
Ni 58.71
copper
29
Cu 63.546
zinc
30
Zn 65.38
gallium
31
Ga 69.72
germanium
32
Ge 72.59
arsenic
33
As 74.922
selenium
34
Se 78.96
bromine
35
Br 79.904
krypton
36
Kr 83.80
rubidium
37
Rb 85.468
strontium
38
Sr 87.62
yttrium
39
Y 88.906
zirconium
40
Zr 91.22
niobium
41
Nb 92.906
molybdenum
42
Mo 95.94
technetium
43
Tc [98]
ruthenium
44
Ru 101.07
rhodium
45
Rh 102.91
palladium
46
Pd 106.4
silver
47
Ag 107.87
cadmium
48
Cd 112.41
indium
49
In 114.82
tin
50
Sn 118.69
antimony
51
Sb 121.75
tellurium
52
Te 127.60
iodine
53
I 126.90
xenon
54
Xe 131.30
caesium
55
Cs 132.91
barium
56
Ba 137.33
lutetium
71
Lu 174.97
hafnium
72
Hf 178.49
tantalum
73
Ta 180.95
tungsten
74
W 183.85
rhenium
75
Re 186.21
osmium
76
Os 190.2
iridium
77
Ir 192.22
platinum
78
Pt 195.09
gold
79
Au 196.97
mercury
80
Hg 200.59
thallium
81
Tl 204.37
lead
82
Pb 207.2
bismuth
83
Bi 208.98
polonium
84
Po [209]
astatine
85
At [210]
radon
86
Rn [222]
francium
87
Fr [223]
radium
88
Ra [226]
lawrencium
103
Lr [262]
rutherfordium
104
Rf [261]
dubnium
105
Db [262]
seaborgium
106
Sg [263]
bohrium
107
Bh [264]
hassium
108
Hs [265]
meitnerium
109
Mt [268]
darmstadtium
110
Ds [269]
roentgenium
111
Rg [272]
copernicium
112
Cn [277]
ununtrium
113
Uut [284]
flerovium
114
Fl [289]
ununpetium
115
*Uup [288]
livermorium
116
Lv [293]
ununseptium
117
*Uus [294]
ununoctium
118
*Uuo [299]
*Discovery reported by not verified
lanthanum
57
La 138.91
cerium
58
Ce 140.12
praseodymium
59
Pr 140.91
neodymium
60
Nd 144.24
promethium
61
Pm [145]
samarium
62
Sm 150.4
europium
63
Eu 151.96
gadolinium
64
Gd 157.25
terbium
65
Tb 158.93
dysprosium
66
Dy 162.50
holmium
67
Ho 164.93
erbium
68
Er 167.26
thulium
69
Tm 168.93
ytterbium
70
Yb 173.04
actinium
89
Ac [227]
thorium
90
Th 232.04
protactinium
91
Pa 231.04
uranium
92
U 238.03
neptunium
93
Np [237]
plutonium
94
Pu [244]
americium
95
Am [243]
curium
96
Cm [247]
berkelium
97
Bk [247]
californium
98
Cf [251]
einsteinium
99
Es [252]
fermium
100
Fm [257]
mendelevium
101
Md [258]
nobelium
102
No [259]
H 2.2
Electron Affinity Table He ---
Li 1.0
Be 1.6
B 2.0
C 2.6
N 3.0
O 3.4
F 4.0
Ne ---
Na 0.9
Mg 1.3
Al 1.6
Si 1.9
P 2.2
S 2.6
Cl 3.2
Ar ---
K 0.8
Ca 1.0
Sc 1.4
Ti 1.5
V 1.6
Cr 1.7
Mn 1.6
Fe 1.8
Co 1.9
Ni 1.9
Cu 1.9
Zn 1.7
Ga 1.8
Ge 2.0
As 2.2
Se 2.6
Br 3.0
Kr ---
Rb 0.8
Sr 1.0
Y 1.2
Zr 1.3
Nb 1.6
Mo 2.2
Tc 2.1
Ru 2.2
Rh 2.3
Pd 2.2
Ag 1.9
Cd 1.7
In 1.8
Sn 2.0
Sb 2.1
Te 2.1
I 2.7
Xe ---
Cs 0.8
Ba 0.9
La 1.1
Hf 1.3
Ta 1.5
W 1.7
Re 1.9
Os 2.2
Ir 2.2
Pt 2.2
Au 2.4
Hg 1.9
Tl 1.8
Pb 1.8
Bi 1.9
Po 2.0
At 2.2
Rn ---
Fr 0.7
Ra 0.9
Ac 1.1
General Physical Constants
Atomic mass unit 1 amu = 1.6605 x 10-24 g
Avogadro’s Number N = 6.02 x 1023 particles/mol
Gas constant R = 8.31 L kPa K-1 mol-1
Ideal gas molar volume Vm = 22.4 L mol-1
Masses of subatomic particles
Electron (e-)
Proton (p+)
Neutron (n0)
me = 0.0005486 amu = 9.1096 x 10-28 g
mp = 1.007277 amu = 1.67261 x 10-24 g
mn = 1.008665 amu = 1.67492 x 10-24 g
Speed of Light (in a vacuum) c = 3.00 x 108 m s-1
Planck’s Constant h = 6.626 x 10-34 J s
Solubility Rules
Negative Ion Rule
NO3- All compounds formed with the negative ion are soluble
I-, Br-, Cl- All compounds formed with the negative ion are soluble except Ag+, Pb2+, Hg2+, and Cu+
SO42-
Most compounds formed with the negative ion are soluble; exceptions include SrSO4, BaSO4, CaSO4, RaSO4, Ag2SO4, and PbSO4
CO32-, PO4
3-, SO3
2-
All compounds formed with the negative ion are insoluble except those of the alkali metals and NH4
+
OH- All compounds formed with the negative ion are insoluble except those of the alkali metals, NH4
+, Sr2+, and Ba2+. (Ca(OH)2 is slightly soluble)
S2- All compounds formed with the negative ion are insoluble except those of the alkali metals, alkaline earth metals, and NH4
+.
Reactivity Series
Metals Halogens
Lithium Potassium Calcium Sodium Magnesium Aluminum Zinc Chromium Iron Nickel Tin Lead Hydrogen Copper Mercury Silver Platinum Gold
Fluorine Chlorine Bromine Iodine
SI Units and Equivalents
Quantity SI Unit Common Equivalents
Length Meter (m) 1 meter = 1.0936 yards 1 centimeter = 0.39370 inch
1 inch = 2.54 centimeters 1 mile = 5280 feet = 1.6093 kilometers
Volume Cubic meter (m3)
1 liter = 10-3 m3 = 1.0567 quarts 1 gallon = 4 quarts = 8 pints = 3.7852 liters
1 quart = 32 fluid ounces = 0.94635 liter
Temperature
Kelvin (K) °C = 5/9 (F -32) K = °C + 273.15
Mass Kilogram (kg)
1 kilogram = 1000 grams = mass weighing 2.2046 pounds
1 amu = 1.66057 x 10-27 kilograms
Time Second (s) 1 hour = 60 minutes = 3600 seconds
Energy Joule (J) 1 joule = 1 kg m2 s-2 (exact) = 0.23901 calorie 1 calorie = 4.184 joules
Pressure Pascal (Pa) 1 atmosphere = 101.3 kilopascals = 760 mm Hg (torr) 1 atmosphere = 14.70 pounds per square inch
Table of Contents
I. Syllabus page i
II. Classroom Map page iv
III. School Safety Drills page v
IV. Lab Safety Contract page vi
V. Unit Objectives page viii
VI. Objective Graphs page xi
VII. Homework
Unit 1: Measurement page 1
Unit 2: Matter & the Atom page 4
Unit 3: Electromagnetic Spectrum page 9
Unit 4: Metals & Ionic Bonding page 14
Unit 6: Covalent Bonding page 19
Unit 7: Moles & Chemical Reactions page 22
VIII. Labs
Significant Figures Lab page 31
Density Lab page 33
Beanium Lab page 36
Spectroscopy Spectrum Lab page 38
Flame Test Lab page 40
Paper Chromatography of Food Dyes page 42
Precipitation Lab page 45
IX. Appendix
Flowchart for Naming Chemical Compounds page A
Flowchart for Writing Formulas for Chemical Compounds page B
VSEPR Sheet page C
Mole Map page D
i
Chemistry I Syllabus
Lincoln College Preparatory Academy
Teacher: Melissa Manakul E-mail:[email protected]
Room: 207 Google Classroom: xbzb8sl
*Any communication to me either through e-mail or Google Classroom will be responded to as soon as humanly possible.
MY WEEKLY SCHEDULE:
Day Monday Tuesday Wednesday Thursday Friday
Morning In classroom by
6:50 am
In classroom by
6:50 am
In classroom by
6:50 am
In classroom by
6:50 am
In classroom by
6:50 am
Afternoon Meeting Tutoring
2:30 – 3:30 Staff Meeting
Will leave by
3:00 pm
Will leave by
2:30 pm
COURSE DESCRIPTION:
Chemistry is an experimental science that combines academic study with the acquisition of practical and investigational
skills. It is called the central science, as chemical principles underpin both the physical environment in which we live and
all biological systems. Apart from being a subject worthy of study in its own right, chemistry is a prerequisite for many
other courses in higher education, such as medicine, biological science and environmental science, and serves as a useful
preparation for employment.
GOALS FOR SEMSTER:
1. You will be prepared for IB Chemistry II, AP Chemistry, or collegiate General Chemistry course.
2. You will be able to raise your ACT score 3 points over the course of the year.
REQUIRED MATERIALS:
Booklet: This is your bible in Chemistry. Each student receives a booklet at the beginning of the semester, which includes
all unit objectives, homework, labs, and supplemental material. This is to go home every night.
Lab Book: This will be a composition notebook (college ruled or grid paper preferred) which will house all your
completed labs and activities. This will be graded throughout the year, and left in the classroom.
Laptop: This will be used to access the textbook and Google Classroom where any announcements, calendar changes,
copies of activities, additional supplemental information, and extra copies of homework. We will also use it for a
variety of activities to be done at home or in the classroom through a variety of educational websites.
SUGGESTED MATERIALS:
Binder/Folder: This will hold any paper work, including but not limited to tests, quizzes, lab reports, and activities. You
must take this home every night. Any time Tyler or my record is incorrect, it is the student’s job to report this to
Ms. Manakul with a graded copy. This is the only way a grade can be changed for full credit.
Scientific Calculator: TI-30x is a preferred calculator, however any scientific calculator will do.
TOPICS COVERED:
(1) Scientific Method (2) Matter & Atomic Structure (3) Electromagnetic Spectrum (4) Ions & Ionic Bonding (5)
Covalent Bonding (6) Moles & Chemical Reactions (7) Stoichiometry (8) Gases (9) Solutions (10)Acids & Bases
(11)Thermochemistry
METHOD OF INSTRUCTION:
We will be moving through material at a steady pace. We will be working through an objective in about a week. There
will be at least 1 quiz per unit and 1 test per unit. There will be around 1 to 2 major labs per unit and activities/discussions
scattered throughout the unit. Participation in labs and activities is a requirement and are done to ensure you properly
comprehend material. You will have homework most nights. All work must be completed for the next class period
unless specified otherwise.
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DO NOWS/EXIT TICKETS:
Do Now’s & Exit Tickets are Ms. Manakul’s way to see who does or does not get what is happening in class. Ms.
Manakul also believes any work that you do should be worth something. Thus, you will turn your Do Now/Exit Ticket in
to Ms. Manakul BEFORE she goes over the answer. If you answer the question correctly your Do Now/Exit Ticket sheet
will go into the class piggy bank. If you would like to save paper, and show the class that “you got this,” you may go over
the answer in Ms. Manakul’s place. If you choose this route, your name will automatically go into the class piggy bank.
Before each quiz Ms. Manakul will pull out two random Do Now/Exit Ticket Sheets and those two people will gain
automatic extra credit towards the quiz. Before a test Ms. Manakul will pull out four sheets. If you are absent, you may
see Ms. Manakul before or after school (not during school) to make up your Do Now so you do not miss out on any of the
extra credit drawing entries.
HOMEWORK:
As mentioned above, homework will be assigned at the end of class and will be due in class the following school day.
Homework is a place to better comprehend material, gain proper practice, and solidify knowledge. However, sometimes
homework is confusing or you did not learn material the first time. Should this happen you should ALWAYS ASK
QUESTIONS either with a classmate or Ms. Manakul. Because we all struggle with homework, Ms. Manakul takes
homework as a completion grade. You must have tried the problem, i.e. you do not necessarily need to complete the
problem. Be aware an IDK is not trying and will thus your homework to be considered incomplete. After the class Do
Now, Ms. Manakul will check homework and go through the homework to ensure everyone comprehends the material.
Remember if you didn’t get it the first time ALWAYS ASK QUESTIONS!
LAB WORK:
Ms. Manakul will go over each lab the day before. You are to prepare your lab book by having your lab book filled out at
home based on the rubric. To prepare you for designing your own lab, each lab is designed to be very similar to your
typed lab report. We will discuss the specifics of the designed lab when we get there. For your safety you will be wearing
lab coats, goggles, and closed toed shoes in the lab room for the majority of labs. If you wear open toed shoes during a
lab, you will wear gloves over your shoes to protect your feet. If this is to change, Ms. Manakul will verbally state it. Ms.
Manakul has high expectations for lab, thus, you will gather, set up, and put away your own lab materials. Furthermore,
YOU MUST BE SAFE at all times during a lab. Ms. Manakul will give ONLY ONE verbal warning. If she must give
another, you will be ejected from lab, and receive an automatic zero for the lab.
LATE WORK:
Ms. Manakul dislikes late work and generally cannot spare the time to regrade items. Thus, any late work will receive
30% off. This means by the 3rd class day, your work will receive an automatic zero. This is to ensure work is turned in a
timely manner, and Ms. Manakul has adequate time to grade your work.
QUIZZES/TESTS:
For every quiz/test you will be given a clean copy of the periodic table. For unit tests only, you will be allowed to have
your own hand written 3” by 5” one sided notecard with any notes you need on them. At the end of the semester you may
take a cumulative test. This will be determined by Ms. Manakul and announced in class when necessary. If you are caught
cheating or talking during a test, Ms. Manakul will take your test and give you an automatic zero. All tests and quizzes are
graded as fast as humanly possible and will be placed in Tyler at the same rate. Any changes will be announced verbally.
ABSENT:
Lesson plans for the week are posted in the classroom. A large calendar is also posted which will label future events as
well. You can also check chemistrywithmanakul.weebly.com for any updates or changes. If you are absent, it is your
responsibility to make up the lecture notes on your own time. Should you need assistance, you may see Ms. Manakul
before or after school (reference My Weekly Schedule). Remember to turn in work as soon as possible. Any work
assigned during your absence will have a 2 school day grace period. If you are absent on the day an assignment is due, it
will be due the first day you return. If you miss a lab or activity, you are to collect the data from a friend, and finish the
rest of your lab report on your own time. *If Ms. Manakul is unexpectedly absent, you are to refer to the lesson plans
posted and watch online for specific details of any work to be completed in class. If an activity or lab is scheduled for that
day, it will be rescheduled. Ms. Manakul will recap all information and class activities/labs will be done with the class
when she returns.
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CLASS RULES:
1. Pay close attention to class, and be prepared to work hard.
2. 10/10 Rule. No passes will be given during the first 10 minutes and the last 10 minutes of class. Restroom passes
only in extreme emergencies. We have very little time and will be moving through material quickly. This means
that class time is IMPORTANT and Ms. Manakul will do her best to maximize the time we have together.
3. IF ABSENT: DON’T GET LEFT BEHIND. Remember chemistry is a class you must practice to understand,
which means missing a day can be essential to failing. Get help! See My Weekly Schedule.
4. Turn in work on time! Every day your work is late you will lose 30% that means that by the end of day 3 your
work will be an automatic zero. Ms. Manakul will give 2 extra days to make up work for every day you have an
excused absent.
5. No food or drinks will be allowed in the lab room. You may eat in the classroom as long as it does not become a
distraction. If you need to throw away large items or liquids, please toss them in trash cans in the hallways.
6. ALL electronic devices except your computer may not be used in the classroom. There will be occasions where
you may use them. Ms. Manakul will either say this or you may ask if the time is appropriate. If the time is
inappropriate the device will be taken on the second verbal warning and can be retrieved by the end of class.
7. Per district policy: Every 3 tardies = detention. Ms. Manakul considers a tardy as not being in the classroom at
the start of class.
GRADES:
A = 90.0 – 100.0 10% Homework
B = 80.0 – 89.9 20% Activities/Discussions
C = 70.0 – 79.9 20% Lab
D = 60.0 – 69.9 20% Quizzes
F = 0.0 – 59.9 30% Tests
Quarter Grades: Based on breakdown Semester Grade: Average of Quarters Year Grades: Average of Semesters
EXTRA CREDIT:
Extra credit is given throughout the school year and will be collected and graded each quarter. Students have the option to
read, analyze, and explain an approved scientific article following the extra credit rubric. Copies of the articles are located
in the Google Classroom under the Extra Credit Tab. Only one extra credit article can be done per quarter, and if one is
not done for the quarter students do not have an option to make it up later. Due dates for extra credit will be announced in
class, on Google Classroom, and will be posted on the calendar in the classroom.
TIPS TO SURVIVING CHEMISTRY:
1. Come to class prepared. If you bring you’re “A” game, you are more likely to get an “A” for the year.
2. Participate in class. The more you participate, the better you learn.
3. Pay attention in class. Ms. Manakul loves tell you exactly what will be on the test. If you’re listening you will
know what to expect and what to do.
4. Do the practice tests as if it was a real test. This will give you a better idea of what you need to study more and
how long you need for each problem so you can manage your time wisely.
5. Keep all your notecards. They will make it easier to study for the semester tests.
6. If you ever think something is wrong on a test, homework, notes, etc. TELL Ms. Manakul right away. We all get
confused; including Ms. Manakul and it is better to get it clarified then answer a problem wrong.
7. Keep up with any missed notes or work. Chemistry BUILDS! Missing one day of class can put you two to three
days behind your classmate, which will make you struggle more during the test.
8. Do your best on all homework and classwork. Practicing chemistry is like a mental workout. The best workouts
are the ones that require the most mental energy, so DON’T GIVE UP, even if it is tough.
9. Do your own work. Copying others’ homework or labs will only hurt you on the quizzes and tests.
10. Get your own your calculator!
iv
Classroom Map
v
School Safety Drills
On this page you will fill in Manakul’s Classroom procedures for all School Safety Drills.
1. Fire Safety
2. Tornado
3. Lock Down
4. Earthquake
5. Where are the maps located for emergency drills?
vi
vii
viii
Chemistry I Semester I Objectives
Unit 1: Measurement
Objective Accomplishment Goal Quiz
You will be able to do complete
mathematical problems in
chemistry
You will be able to set up
dimensional
analysis/conversions and
scientific notation problems to
ensure a change in units.
You will be able to report
quantitative results with the
correct number of significant
figures and in correct scientific
notation.
You know how to write numbers
in scientific notation and know
all the rules of significant
figures.
Unit 2: Matter & Atom
Objective Accomplishment Goal Quiz Test
You can distinguish between an
element, compound, and
chemical reaction.
You are able to distinguish
between elements, compound,
and list the 6 types of chemical
reactions.
You are able to describe the
progression of scientific work
in distinguishing components of
the atom.
You can describe the
experiments associated with the
scientists who discovered the
atom and its components
You are able to distinguish the
components of the atom, and
calculate the average atomic
mass of an element.
You are can to determine the
number of electrons, protons,
neutrons, mass number, charge,
and atomic number when given
a combination of these. You can
calculate the average atomic
mass and know which isotope is
more abundant given specific
data.
You will be able to explain how
radioactive decay works.
You can complete radioactive
decay equations.
Unit 3: Electromagnetic Spectrum
Objective Accomplishment Goal Quiz Test
You will be able to explain the
atomic emission spectra by
transition of electrons between
energy levels.
You can calculate frequency and
wavelength of emitted light
using Plank’s constant and
explain what photoelectric effect
is.
You can explain how electrons
are arranged the modern atom
structure.
You can organize electrons in
any element by their energy
order and orbital type.
ix
You will be able to explain
how elements are organized in
the periodic table.
You can identify each element
as either a metal, metalloid, or a
non-metal and determine the
element’s family name.
You will be able to explain
periodic trends.
You can explain ion formation,
atomic radius, ionization energy,
and electronegativity energy.
Unit 4: Metals & Ionic Bonding
Objective Accomplishment Goal Quiz Test
You are able to define valence
electrons and determine their
number for a particular group
of chemical elements, explain
octet rule and Lewis dot
diagrams, which atoms are
likely to lose or gain electrons,
how cations and anions form.
You can explain why
representative elements like to
be noble gases, and draw a
picture to depict what a
representative element looks like
as a cation or anion.
You can explain the formation
of Lattice Structures and its
determination of chemical and
physical properties for a
compound.
You can determine the
coordination number for a
compound and describe the
different types of lattice
structures.
You can explain how ionic and
metallic bonds are formed,
describe the properties of each,
and explain why alloys are
important.
You can list at least three
properties of an ionic and
metallic compound, and explain
the importance of alloys.
Unit 5: Covalent Bonding
Objective Accomplishment Goal Quiz Test
You can explain how electrons
are shared in covalent bonds,
what are coordinate covalent
bonds, compare and contrast
ionic and covalent bonds.
You can draw covalent
compounds and their resonance
structures.
You can explain the difference
between atomic and molecular
orbitals, predict the shapes of
molecules
You can determine a covalent
compounds shape using VSEPR
theory.
Molecules using VSEPR
theory, and explain how
bonding occurs between
molecules.
You can use VSEPR theory to
explain polarity within a
covalent compound and the
attraction between compounds.
x
Unit 6: Moles & Chemical Reactions
Objective Accomplishment Goal Quiz Test
You will be able to execute
conversion problems
You are able to determine the
givens, set up the train tracks,
and execute your solution.
You will be able to explain
what a mole is and use it in
conversion problems
You can explain what a mole is
and be able to write it as a
conversion factor.
You will be able to determine
the chemical formula of an
ionic or covalent compound.
You are able to determine if a
compound is going to be ionic or
covalent and then write its
chemical formula based on its
name.
You will be able to calculate
percent composition of a
chemical compound.
You can set up the steps to
determine percent composition
of a chemical compound.
xi
Objective Graphs
On this page you will create a bar graph for each unit of your goal, quiz and test scores per
objective (these are obtained from the trackers done after each quiz and test). Use test data for
best accuracy & remember to put units and labels. SUGGESTION: Use different colors.
Unit 1: Measurement Unit 2: Matter & Atom
Unit 3: Electromagnetic Spectrum Unit 4: Metals & Ionic Bonding
xii
Unit 5: Covalent Bonding Unit 6: Moles & Chemical Reactions
Spare Graphs
1
Unit 1: Measurement Homework
SECTION 1.1: MEASUREMENTS AND THEIR UNCERTAINTY
1. Explain why there are two units for density (g/L vs. g/m3)?
2. If the temperature in Europe is 23.0°C, what would this temperature be in Fahrenheit
(°F)?
3. If the temperature in the lab is 73.2°F, what is the temperature in Kelvin?
4. Determine the number of significant figures are in the following numbers:
a. 209 m
b. 4140 inches
c. 1.330 mi
d. 0.0034 cm
e. 3.22 x 1016 g
f. 214 dogs
5. Perform the following operations (try these without a scientific calculator):
a. 2.567 m x 0.00456 m
b. 103 L / 2.33 L
c. 6.23 x 102 g + 5.33 x 103 g
d. 7.34 x 10-2 cm – 1.33 x 10-1 cm
2
Use the following information to answer questions 6-11.
Using different rulers, Bruce and Pete each measured the length of the same object three times.
Bruce’s three measurements are 19 cm, 20 cm, and 22 cm. Pete’s three measurements are 20.9
cm, 21.0 cm, and 21.0 cm.
6. Calculate the average value of Bruce’s measurements and express the answer with the
correct number of significant figures.
7. Calculate the average value of Pete’s measurements and express the answer with the
correct number of significant figures.
8. Whose measurements are more precise?
9. The actual length of the object is 20 cm. whose measurements are more accurate?
10. What is the error of Pete’s average measurement?
11. What is the percent error of Pete’s average measurement?
3
SECTION 1.2: CONVERIONS
1. Convert the following quantities. See periodic table for necessary information.
a. 565,900 seconds into days
b. 17 years into minutes
c. 43 miles into feet
d. 165 pounds into kilograms
e. 27 milliohms to ohms
f. 49 micrometers to meters
g. 469 Joules to calories
4
Unit 2: Matter & Atom Homework
SECTION 2.1 PROPERTIES OF MATTER 1. Complete the following table.
Physical state Definite Shape? Definite
Volume?
Easily
Compressed?
gas
no no
yes
2. Which of the following is not a type of matter?
a. plasma b. aqueous c. solid d. gas
3. Which of the following is not a property of a gas?
a. has a definite shape c. assumes the shape of its container
b. has an indefinite volume d. is easily compressed
4. Which of the following is not a physical property of sucrose?
a. solid at room temperature c. dissolves in water
b. decomposes when heated d. tastes sweet
5. Which of the following is in a different physical state at room temperature than the other
three?
a. salt b. sugar c. flour d. water
6. Classify the following properties as extensive or intensive.
a. color b. volume c. mass d. boiling point
SECTION 2.2 MIXTURES
1. How might you separate a mixture of water and salt?
2. What is a homogeneous mixture?
3. Which of the following mixtures are homogeneous? Which are heterogeneous?
a. gasoline b. chunky peanut butter c. oil and vinegar salad dressing
4. Which of the following are substances? Which are mixtures?
a. ethanol b. motor oil c. vinegar d. neon
5. Classify the following as elements, compounds, or mixtures.
a. table salt b. water c. iron d. stainless steel
5
SECTION 2.3 ELEMENTS AND COMPOUNDS
1. What elements make up ammonia, chemical formula NH3?
2. Name the elements represented by the following chemical symbols.
a. Pb b. K c. Au d. Fe
3. Write the chemical symbol for each of the following elements.
a. tin b. sodium c. silver d. carbon
4. A liquid is allowed to evaporate and leaves no residue. Can you determine whether it was
an element, a compound, or a mixture? How?
5. Which of the following is not an element?
a. copper c. sulfur
b. sucrose d. helium
SECTION 2.4 CHEMICAL REACTIONS
1. Which one of the following is a chemical change?
a. Gasoline boils. c. Gasoline burns.
b. Oxygen is added to gasoline. d. Gasoline is poured into a tank.
2. Classify each of the following changes as physical or chemical.
a. A puddle is dried by the sun. c. Bread is toasted.
b. A dark cloth is faded by sunlight. d. Soap is mixed with water.
3. Which of the following is not a type of chemical reaction?
a. combustion c. triple replacement
b. double replacement d. decomposition
4. Carbon dioxide plus water yields carbonic acid.
a. Name the product(s) of this reaction.
a. Name the reactant(s) of this reaction.
6
5. List 3 key terms to determine a physical change.
6. List 3 key terms to determine a chemical change.
7. Which of the following is not a physical change?
a. dissolving sugar in water c. evaporating sea water to obtain salt
b. burning gasoline in an engine d. slicing a piece of bread
SECTION 2.5 STRUCTURE OF THE NUCLEAR ATOM
1. A sulfur-32 atom contains 16 protons, 16 neutrons, and 16 electrons. What is the mass (in
grams) of a sulfur-32 atom?
2. The mass of a neutron is 1.67 x 10-24 g; approximately what number of neutrons would
equal a mass of one gram?
3. Which statement is consistent with the results of Rutherford’s gold foil experiment?
a. All atoms have a positive charge.
b. Atoms are mostly empty space.
c. The nucleus of an atom contains protons and electrons.
d. Mass is spread uniformly throughout an atom.
SECTION 2.6 DISTINGUISHING BETWEEN ATOMS
1. How many protons are found in an atom of each of the following?
a. boron c. neon
b. sulfur d. lithium
2. How many neutrons are in each atom?
a. c.
b. d.
23 Na 11
81 Br 35
238 U 92
19 F 9
7
3. Complete the table for the following elements.
Element Number of
Protons
Number of
Electrons
Number of
Neutrons
Atomic
Number
Mass
Number
Manganese 25 30
Sodium 11 12
Bromine 35 45
Yttrium 39 89
Arsenic 33 75
Actinium 227
4. The two most abundant isotopes of carbon are carbon-12 (mass = 12.00 amu) and carbon-
13 (mass = 13.00 amu). Their relative abundances are 98.9% and 1.10%, respectively.
Calculate the atomic mass of carbon.
5. Element X has two isotopes: X-100 and X-104. If the atomic mass of X is 101 amu, what
is the relative abundance of each isotope in nature?
8
SECTION 2.7: Nuclear Chemistry
1. Identify the following as alpha, beta, gamma, or neutron.
a. 1
0 n
b. 0
−1 e
c. 4
2 He
d. 0
0 γ
e. Nuclear decay with no mass and no charge.
f. An electron.
g. Least penetrating nuclear decay.
h. Most damaging nuclear decay to the human body.
i. Nuclear day that can be stopped by skin or paper.
j. Nuclear decay that can be stopped by aluminum.
2. Complete the following nuclear equations.
a. 42
19𝐾 →
0
−1𝑒 + ________ d.
239
94𝑃𝑢 →
4
2𝐻𝑒 + ________
b. 9
4𝐵𝑒 →
9
4𝐵𝑒 + ________ e.
235
92𝑈 → _______ +
231
90𝑇ℎ
c. 6
3𝐿𝑖 →
4
2𝐻𝑒 + ________ f. _______ →
142
56𝐵𝑎 +
91
36𝐾𝑟 + 3
1
0𝑛
9
Unit 3: Electromagnetic Spectrum
SECTION 3.1 MODELS OF THE ATOM
1. How many sublevels are in the following principal energy levels?
a. n = 1 c. n = 3 e. n = 5
b. n = 2 d. n = 4 f. n = 6
2. How many orbitals are in the following sublevels?
a. 1s sublevel d. 4f sublevel g. fifth principal energy level
b. 5s sublevel e. 7s sublevel h. 6d sublevel
c. 4d sublevel f. 3p sublevel
3. What are the types of sublevels and number of orbitals in the following energy levels?
a. n = 1 c. n = 3 e. n = 5
b. n = 2 d. n = 4
SECTION 3.2 ELECTRON ARRANGEMENTS IN ATOMS
1. Write a complete electron configuration of each atom.
a. hydrogen d. barium g. krypton
b. vanadium e. bromine h. arsenic
c. magnesium f. sulfur i. radon
10
SECTION 3.3 PHYSICS AND THE QUANTUM MECHANICAL MODEL
1. What is the wavelength of the radiation whose frequency is 5.00 × 1015 s–1? In what region
of the electromagnetic spectrum is this radiation?
2. An inexpensive laser that is available to the public emits light that has a wavelength of 670
nm. What are the color and frequency of the radiation?
3. What is the energy of a photon whose frequency is 2.22 × 1014 s–1?
4. What is the frequency of a photon whose energy is 6.00 × 10–15 J?
5. Arrange the following types of electromagnetic radiation in order of increasing frequency.
a. infrared c. visible light e. microwaves
b. gamma rays d. radio waves f. ultraviolet
6. Suppose that your favorite AM radio station broadcasts at a frequency of 1600 kHz. What
is the wavelength in meters of the radiation from the station?
11
SECTION 3.4 ORGANIZING THE ELEMENTS
1. Which element listed below should have chemical properties similar to fluorine (F)?
a. Li b. Si c. Br d. Ne
2. Identify each element as a metal, metalloid, or nonmetal.
a. fluorine
b. germanium
c. zinc
d. phosphorus
e. lithium
3. Which of the following is not a transition metal?
a. Magnesium b. titanium c. chromium d. mercury
4. Name two elements that have properties similar to those of the element potassium
5. Elements in the periodic table can be divided into three broad classes based on their
general characteristics. What are these classes and how do they differ?
SECTION 3.5 CLASSIFYING THE ELEMENTS
1. Use the periodic table to write the electron configuration for silicon. Explain why silicon
is considered a metalloid and representative element.
2. Use the periodic table to write the electron configuration for iodine. Explain why iodine
is classified as a halogen.
3. Which group of elements is characterized by an s2p3 configuration?
12
4. Name the element that matches the following description.
a. one that has 5 electrons in the third energy level
b. one with an electron configuration that ends in 4s24p5
c. the Group 6A element in period 4
5. Identify the elements that have electron configurations that end as follows.
a. 2s22p4
b. 4s2
c. 3d104s2
6. What is the common characteristic of the electron configurations of the elements Ne and
Ar? In which group would you find them?
7. Why would you expect lithium (Li) and sulfur (S) to have different chemical and physical
properties?
8. What characterizes the electron configurations of transition metals such as silver (Ag)
and iron (Fe)?
13
SECTION 3.6 PERIODIC TRENDS
1. Explain why a magnesium atom is smaller than atoms of both sodium and calcium.
2. Predict the size of the astatine (At) atom compared to that of tellurium (Te). Explain your
prediction.
3. Would you expect a Cl– ion to be larger or smaller than an Mg2+ ion? Explain.
4. Which effect on atomic size is more significant, an increase in nuclear charge across a
period or an increase in occupied energy levels within a group? Explain.
5. Explain why the sulfide ion (S2–) is larger than the chloride ion (Cl–).
6. Compare the first ionization energy of sodium to that of potassium.
7. Compare the first ionization energy lithium to that of beryllium.
8. Is the electro negativity of barium larger or smaller than that of strontium? Explain.
9. What is the most likely ion for magnesium to form? Explain.
10. Arrange oxygen, fluorine, and sulfur in order of increasing electro negativity.
14
Unit 4: Metals & Ionic Bonding
SECTION 4.1 IONS
1. For each element below, state (i) the number of valence electrons in the atom, (ii) the
electron dot structure, and (iii) the chemical symbol(s) for the most stable ion.
a. Ba b. I c. K
2. How many valence electrons does each of the following atoms have?
a. gallium b. fluorine c. selenium
3. Write the electron configuration for each of the following atoms and ions.
a. Ca c. Na+ e. O2–
b. chlorine atom d. phosphide ion
4. What is the relationship between the group number of the representative elements and the
number of valence electrons?
5. How many electrons will each element gain or lose in forming an ion? State whether the
resulting ion is a cation or an anion.
a. strontium c. tellurium e. bromine
b. aluminum d. rubidium f. phosphorus
6. Give the name and symbol of the ion formed when
a. a chlorine atom gains one electron.
b. a potassium atom loses one electron.
c. an oxygen atom gains two electrons.
d. a barium atom loses two electrons.
15
7. How many electrons are lost or gained in forming each of the following ions?
a. Mg2+ b. Br– c. Ag+ d. Fe3+
8. Classify each of the following as a cation or an anion.
a. Na+ c. I– e. Ca2+
b. Cu2+ d. O2– f. Cs+
SECTION 4.2 NAMING IONS
1. What is the charge on the ion typically formed by each element?
a. Oxygen c. sodium e. nickel, 2 electrons lost
b. iodine d. aluminum f. magnesium
2. How many electrons does the neutral atom gain or lose when each ion forms?
a. Cr3+ c. Li+ e. Cl–
b. P3– d. Ca2+ f. O2–
3. Name each ion. Identify each as a cation or an anion.
a. Sn2+ c. Br– e. H–
b. Co3+ d. K+ f. Mn2+
4. Write the formula (including charge) for each ion. Use Table 9.3 if necessary.
a. carbonate ion c. sulfate ion e. chromate ion
b. nitrite ion d. hydroxide ion f. ammonium ion
16
5. Name the following ions. Identify each as a cation or an anion.
a. CN– c. PO43– e. Ca2+
b. HCO3– d. Cl– f. SO32–
SECTION 4.3 IONIC BONDS AND IONIC COMPOUNDS
1. Use electron dot structures to predict the formula of the ionic compounds formed when
the following elements combine.
a. sodium and bromine d. aluminum and oxygen
b. sodium and sulfur e. barium and chlorine
c. calcium and iodine
2. Which of these combinations of elements are most likely to react to form ionic
compounds?
a. sodium and magnesium c. potassium and iodine
b. barium and sulfur d. oxygen and argon
3. What is the meaning of coordination number?
4. How is the coordination number determined?
17
SECTION 4.4 NAMING AND WRITING FORMULAS FOR IONIC COMPOUNDS
1. Write the formulas for these binary ionic compounds.
a. magnesium oxide c. potassium iodide e. sodium sulfide
b. tin(II) fluoride d. aluminum chloride f. ferric bromide
2. Write the formulas for the compounds formed from these pairs of ions.
a. Ba2+, Cl– c. Ca2+, S2– e. Al3+, O2–
b. Ag+, I– d. K+, Br– f. Fe2+, O2–
3. Name the following binary ionic compounds.
a. MnO2 c. CaCl2 e. NiCl2 g. CuCl2
b. Li3N d. SrBr2 f. K2S h. SnCl4
4. Write formulas for the following ionic compounds.
a. sodium phosphate c. sodium hydroxide e. ammonium chloride
b. magnesium sulfate d. potassium cyanide f. potassium dichromate
5. Write formulas for compounds formed from these pairs of ions.
a. NH4+, SO4
2– c. barium ion and hydroxide ion
b. K+, NO3– d. lithium ion and carbonate ion
18
6. Name the following compounds.
a. NaCN c. Na2SO4 e. Cu(OH)2
b. FeCl3 d. K2CO3 f. LiNO3
7. Name and give the charge of the metal cation in each of the following ionic compounds.
a. Na3PO4 c. CaS e. FeCl3
b. NiCl2 d. K2S f. CuI
SECTION 4.5 BONDING IN METALS
1. What is a metallic bond?
2. How is the electrical conductivity of a metal explained by metallic bonds?
3. Are metals crystalline? Explain.
4. Give three possible crystalline arrangements of metals. Describe each.
5. What is an alloy?
6. Name the principal elements present in each of the following alloys.
a. brass d. sterling silver
b. bronze e. cast iron
c. stainless steel f. spring steel
19
Unit 5: Covalent Bonding
SECTION 5.1 MOLECULAR COMPOUNDS
1. Classify each of the following as an atom or a molecule.
a. Be c. N2 e. Ne
b. CO2 d. H2O
2. Which of the following are diatomic molecules?
a. CO2 c. O2 e. CO
b. N2 d. H2O
3. What types of elements tend to combine to form molecular compounds?
4. What information does a molecule’s molecular structure give?
5. How do ionic compounds and molecular compounds differ in their relative melting and
boiling points?
SECTION 5.2 NAMING AND WRITING FORMULAS FOR MOLECULAR
COMPOUNDS
1. Name the following molecular compounds.
a. PCl5 c. NO2 e. P4O6 g. SiO2
b. CCl4 d. N2F2 f. XeF2 h. Cl2O7
2. Write the formulas for the following binary molecular compounds.
a. nitrogen tribromide c. sulfur dioxide
b. dichlorine monoxide d. dinitrogen tetrafluoride
20
SECTION 5.3 THE NATURE OF COVALENT BONDING
1. Draw the electron dot structure for hydrogen fluoride, HF.
2. Draw the electron dot structure for phosphorus trifluoride, PF3.
3. Draw the electron dot structure for nitrogen trichloride, NCl3.
4. How many resonance structures can be drawn for CO32–? Show the electron dot
structures for each.
SECTION 5.4 BONDING THEORIES
1. Predict the shape and bond angle for the compound carbon tetrafluoride, CF4.
2. Predict the shape and bond angle for phosphorus trifluoride, PF3.
3. Predict the shape and bond angle of xenon tetrachloride, XeCl4.
4. Predict the shape and bond angle of sulfur hexafluoride, SF6.
21
SECTION 5.5 POLAR BONDS AND MOLECULES
1. What type of bond—nonpolar covalent, polar covalent, or ionic—will form between each
pair of atoms?
a. Na and O b. O and O c. P and O
2. Explain why most chemical bonds would be classified as either polar covalent or ionic.
3. Would you expect carbon monoxide and carbon dioxide to be polar or nonpolar
molecules?
4. Draw the structural formulas for each molecule and identify polar covalent bonds by
assigning the slightly positive (δ+) and slightly negative (δ –) symbols to the appropriate
atoms.
a. NH3 b. CF3
5. Which would you expect to have the higher melting point, CaO or CS2?
22
Unit 6: Moles & Chemical Reactions Homework
SECTION 6.1 THE MOLE: A MEASUREMENT OF MATTER
1. What is the molar mass of sucrose (C12H22O11)?
2. What is the molar mass of each of the following compounds?
a. phosphorus pentachloride (PCl5)
b. uranium hexafluoride (UF6)
3. Calculate the molar mass of each of the following ionic compounds:
a. KMnO4
b. Ca3(PO4)2
4. How many moles is 3.52 × 1024 molecules of water?
5. How many atoms of zinc are in 0.60 mol of zinc?
6. What is the mass of 1.00 mol of oxygen (O2)?
23
SECTION 6.2 MOLE–MASS AND MOLE–VOLUME RELATIONSHIPS
1. What is the molar mass of each of the following compounds?
a. C6H12O6 b. NaHCO3 c. C7H12 d. KNH4SO4
2. Calculate the mass in grams of each of the following:
a. 8.0 mol lead oxide (PbO)
b. 0.75 mol hydrogen sulfide (H2S)
c. 0.00100 mol silicon tetrahydride (SiH4)
d. 1.50 × 10–2 mol molecular oxygen (O2)
e. 2.30 mol ethylene glycol (C2H6O2)
3. How many grams are in 1.73 mol of dinitrogen pentoxide (N2O5)?
24
4. How many grams are in 0.658 mol of calcium phosphate [Ca3(PO4)2]?
5. Calculate the number of moles in each of the following:
a. 0.50 g sodium bromide (NaBr)
b. 13.5 g magnesium nitrate [Mg(NO3)2]
c. 1.02 g magnesium chloride (MgCl2)
d. 0.00100 g monochloromethane (CH3Cl)
e. 1.50 × 10–3 g propylene glycol [C3H6(OH)2]
6. A chemist plans to use 435.0 grams of ammonium nitrate (NH4NO3) in a reaction. How
many moles of the compound is this?
7. A solution is to be prepared in a laboratory. The solution requires 0.0465 mol of quinine
(C20H24N2O2). What mass, in grams, should the laboratory technician obtain in order to
make the solution?
25
8. What is the volume at STP of 2.66 mol of methane (CH4) gas?
9. How many moles is 135 L of ammonia (NH3) gas at STP?
SECTION 6.3 PERCENT COMPOSITION AND CHEMICAL FORMULAS
1. A sample of a compound analyzed in a chemistry laboratory consists of 5.34 g of carbon,
0.42 g of hydrogen, and 47.08 g of chlorine. What is the percent composition of this
compound?
2. Find the percent composition of a compound containing tin and chlorine if 18.35 g of the
compound contains 5.74 g of tin.
3. If 3.907 g of carbon combines completely with 0.874 g of hydrogen to form a compound,
what is the percent composition of this compound?
26
4. From the formula for calcium acetate, Ca(C2H3O2)2, calculate the mass of carbon that can
be obtained from 65.3 g of the compound.
5. How many grams of aluminum are in 25.0 g of aluminum oxide (Al2O3)?
6. How many grams of iron are in 21.6 g of iron(III) oxide (Fe2O3)?
7. Determine the empirical formula of each of the following compounds from the percent
composition:
a. 7.8% carbon and 92.2% chlorine
b. 10.0% C, 0.80% H, 89.1% Cl
27
SECTION 6.4 DESCRIBING CHEMICAL REACTIONS
1. Write the skeleton equation for the reaction between hydrogen and oxygen that produces
water.
2. Write the skeleton equation for the reaction that produces iron(II) sulfide from iron and
sulfur.
3. Write the skeleton equation representing the heating of magnesium carbonate to produce
solid magnesium oxide and carbon dioxide gas.
4. Write a balanced equation for the production of HCl gas from its elements.
5. Write a sentence that completely describes the chemical reaction represented by this
balanced equation.
2HCl(aq) + CaCO3(s) CO2(g) + CaCl2(aq) + H2O(l)
6. Write the word equation for the following equation. Write a sentence fully describing the
reaction. Is the equation correctly balanced? Explain.
2Ag(s) + S(s) Ag2S(s)
7. Write a balanced equation representing the formation of aqueous sulfuric acid from water
and sulfur trioxide gas.
28
8. Write a balanced equation from this word equation.
aqueous silver nitrate + copper metal silver metal + aqueous copper nitrate
9. Write a balanced equation for the following word equation.
phosphorus + oxygen tetraphosphorous decoxide
SECTION 6.5 TYPES OF CHEMICAL REACTIONS
1. Write a balanced equation representing the reaction of magnesium with oxygen gas to
produce magnesium oxide.
2. Write the balanced equation for the reaction that occurs between aluminum and fluorine.
3. Write the balanced equation for the production of oxygen gas and potassium chloride
from the decomposition of potassium chlorate.
4. Write the balanced equation for the reaction between hydrochloric acid and calcium
metal. The products are hydrogen gas and calcium chloride.
5. Write the balanced equation for the combustion of propane (C3H8) to produce carbon
dioxide and water vapor.
29
6. Write the balanced equation for the reaction between iron(III) chloride and sodium
hydroxide. The products are iron(III) hydroxide and sodium chloride.
7. Classify each of the reactions in problems 1–6 as to type.
8. Use the activity series of metals (Table 11.2) and your knowledge of the relative
reactivity of the halogens to predict whether the following reactions will occur. Write
balanced equations for those reactions that do occur.
a. Br2(l) + NaCl(aq) →
b. Ca(s) + Mg(NO3)2(aq) →
c. K(s) + H2SO4(aq) →
d. Zn(s) + NaOH(aq) →
SECTION 6.6 REACTIONS IN AQUEOUS SOLUTION
1. Write the net ionic equation for the reaction between aqueous barium nitrate, Ba(NO3)2,
and sodium sulfate, Na2SO4.
2. Magnesium reacts with HCl to form hydrogen and magnesium chloride. Write the
balanced net ionic equation for this reaction.
30
3. The double-replacement reaction below results in the formation of the precipitate lead
chloride. Balance the equation and write the net ionic equation.
a. Pb(NO3)2(aq) + NH4Cl(aq) → PbCl2(s) + NH4NO3(aq)
4. Identify the precipitate formed when solutions of the following ionic compounds are
mixed. If no precipitate is formed, write no precipitate.
a. Zn(NO3)2 + SnCl2 →
b. KCl + AgNO3 →
c. Cu(NO3)2 + Na2S →
d. Al2(SO4)3 + 3Mg(OH)2 →
31
Significant Figures Lab
Background:
This lab will test your skills with a triple balance beam and a graduated cylinder. A
mechanical balance works on the principle that equal masses will be pulled downwards by
gravity with equal force. Thus, if two equal masses are suspended by a string around a pulley,
they balance each other out. Hence the name balance beam. A triple balance beam uses three
(triple) balances to create equivalent mass as what is being weighted. Calibrating a triple balance
beam requires accurate sight and motion control. By calibrating or zeroing the balance (placing
all weights onto the zero marker, then adjusting the left side of the beam so to create a perfect
line from the left to the right side of the beam) the user ensures more accurate results. A
calibrated triple balance beam will give users accurate measurements up to five significant
figures (see information about significant figures below).
A graduated cylinder is considered a measuring cylinder, and is used to measure the
volume of a liquid, generally in milliliters. There are different types of graduated cylinders: 10
ml, 25ml, 50ml, and 100ml will be available in the lab room. Each has its own grading divisions,
for instance 100 mL cylinders have 1 mL grading divisions while 10 ml cylinders have 0.1 ml
grading divisions.
Any measurement established from a scientific tool requires good eye sight and some
estimation like the triple balance beam. To do this, you will need to move the weights so that the
scale re-aligns. The value of the measurement will be the summation of all the weights.
Likewise, when liquid is poured into a graduated cylinder, it creates a meniscus at the top of the
liquid (looks like a small concave curve at the top of the liquid). Almost all liquids create a
meniscus, because of the capillary (attractive) force which occurs between most liquids and the
sides of the graduated cylinder. When measuring the value of a graduated cylinder you must
determine its value from the bottom of the meniscus.
Significant figures are the value of the measurement which is reported. When reading
scales, the amount of significant figures is determined by the grading divisions on the tool plus
one. For instance the 100 mL graduated cylinder has 1 mL grading divisions. Thus, a
measurement on a graduated cylinder would report a value with one decimal place. The plus one
value is included in measurements to ensure all variations that could occur. Many times a
meniscus will not be directly on a line, thus the scientist must estimate its final location, hence
the added digit.
When doing calculations with significant figures there are a couple rules to follow.
1. When adding and subtracting, the smallest amount of decimals must be the same
as your final number.
2. When multiplication and division, the smallest number of digits must be the same
as your final number.
Since your measurements are done through estimation, your final digit will contain
uncertainty. The measurement uncertainty is often taken as the standard deviation of a state-of-
knowledge probability distribution over the possible values that could attribute to a measured
quantity. For Chemistry I, you will be judging this uncertainty through error calculation, which
the equation is given below.
𝑃𝑒𝑟𝑐𝑒𝑛𝑡 𝐸𝑟𝑟𝑜𝑟 = |𝐴𝑐𝑡𝑢𝑎𝑙 𝑤𝑒𝑖𝑔ℎ𝑡 − 𝑒𝑥𝑝𝑒𝑟𝑖𝑚𝑒𝑛𝑡𝑎𝑙 𝑤𝑒𝑖𝑔ℎ𝑡|
𝐴𝑐𝑡𝑢𝑎𝑙 𝑊𝑒𝑖𝑔ℎ𝑡 × 100
32
Objective:
1. Students gain experience with various scientific tools and learn best practices with each
tool.
2. Students will be able to determine the number of significant figures/digits for each
scientific tool.
Materials:
Triple Balance Beam
Nuts and Bolts Bag
100 mL Graduated cylinder
250 mL Beaker
250 mL Flask
Lab Book
Pencil or Black or Blue Pen
Methods:
In this lab you will be conducting two lab experiments. During each lab you must
determine the proper number of significant figures/digits for each scientific tool when recording
data. Then you will need to utilize the rules of significant figures to make and report the correct
end values for each experiment.
In the first lab you are working towards determining the mass of a single washer, bolt,
and nut. In your Nuts & Bolts Bag you will see several bolts, nuts, and washer glued together.
On some bolts you will have more than one nut, and on some bolts you will have more than one
washer. You will need to weigh each bolt combination individually. Then do some creative
calculations to determine the weight of one bolt, one nut, and one washer. The triple balance
beam used to weight each combination should be calibrated or zeroed before weighting each
combination. This is to ensure accurate results are recorded. All weights should be placed into
the Nuts & Bolts Lab Data Table provided in the data recording section. All calculations done
should be placed under the data processing section.
In the second lab you will be comparing the density of water in a 250 mL Beaker, 250
mL Flask, and a graduated cylinder. To do this you will need to record the mass of 50 mL of
water in each of the vessels. Thus, determine the mass of each vessel, the mass of each vessel
with 50 mL of water, the mass of water within each vessel, and the density of pure water. Record
all values in the Density of Water Comparison Data Table, and do all calculations under the data
processing section. (Hint: the actual density of water is 1.0 g/ml)
Safety:
For your safety it is important to proceed with caution. The bolt, nut, and washer combinations
are heavy and can cause severe damage to the lab room and to people if thrown or mishandled.
Likewise, you are handling glassware, which should always be inspected for cracks before use,
has the ability to shatter, especially when heated. Thus, handle glassware with extreme caution.
Should you shatter or break any glassware, Alert Ms. Manakul immediately, and ensure no one
touches the broken glassware. Ms. Manakul will handle the cleaning processes. Since we are not
heating glassware, you will not be required to wear goggles or lab coats for this lab. However,
closed toed shoes must be worn at all times. Hard toed shoes would be preferable since the bolt,
nut, and washer combinations are heavy and can cause damage to a person’s foot if dropped on
to them. Likewise stepping on broken glass or having glassware break on your feet is dangerous.
This lab has no environmental concerns, since no hazardous materials are being utilized.
32
Data Recording:
Nuts & Bolts Data Table
Weight (g)
Com
bin
ati
on
s
1 Bolt, 1 Nut, 1 Washer
1 Bolt, 3 Nuts, 0 Washer
1 Bolt, 1 Nut, 3 Washers
1 Bolt, 1 Nut, 2 Washers
1 Bolt, 2 Nuts, 2 Washer
Density of Water Comparison Data Table
Vessel Mass of Vessel Mass of Vessel +
Water
Mass of Water
250 mL Beaker
250 mL Flask
100 mL Graduated
Cylinder
Data Processing:
1. Calculate the weight of each individual bolt, nut, and washer.
(Weight of 1 Bolt, 1 Nut, 3 Washers) – (Weight of 1 Bolt, 1 Nut, 2 Washers) = Weight of 1
Washer
2. Calculate your percent error for a bolt, nut, and washer. You will need the actual weights
for the bolt, nut, and washer. Ask Ms. Manakul for this data when you reach this step.
Remember to show all work.
3. Calculate the density of water for each vessel. Show all work here. Calculate the percent
error for each vessel. You will need the actual density of water. Ask Ms. Manakul for this
data when you reach this step. Remember to show all work.
Challenge Questions:
1. Explain why having accurate significant figures, especially when doing calculations, is
important to the scientific community.
2. You were supposed to get large values of percent error for the bolt, nut, and washer.
Why?
3. Why was using tap water in experiment two not going to give us the best values?
Conclusion & Evaluation
1. Write your own conclusion and evaluation of this lab.
33
Density Lab
Background:
The density, or more precisely, the volumetric mass density, of a substance is its mass per unit
volume. The symbol most often used for density is ρ (the lower case Greek letter rho).
Mathematically, density is defined as mass divided by volume, where ρ is the density, m is the
mass, and V is the volume.
𝜌 = 𝑚𝑎𝑠𝑠
𝑣𝑜𝑙𝑢𝑚𝑒=
𝑚
𝑉
For a pure substance the density has the same numerical value as its mass concentration.
Different materials usually have different densities, and density may be relevant to buoyancy,
purity and packaging. The density of a material varies with temperature and pressure. This
variation is typically small for solids and liquids but much greater for gases. Below is a simple
list of densities of some common materials:
Solids and Liquids
Material Density at 20°C (kg/m3)
Gold 19.3
Mercury 13.6
Lead 11.3
Aluminum 2.70
Glass (flint) 2.9-5.9
Silver 10.5
Brass 8.49
Diamond 3-3.5
Epoxy glass fiber 1.5
Iron 7.87
Objectives:
1. You will be able to determine the substance of the compound based on its density.
2. You will gain practice calculating using conversions.
Materials:
1 white/clear marble
1 silver marble
Triple balance beam
Weigh boat
10 mL graduated cylinder
Tap water
50 mL Beaker
Methods:
In this lab you will be determining what the white/clear and silver marble are made of based on
their densities. You will use the graduated cylinder to find the volume of each marble. You will
first need to fill your 50 mL beaker with some tap water (DO NOT use the distilled water). Once
you have your water you can fill your 10 mL graduated cylinder with 5 mL of water. Once you
have the bottom meniscus on the 5 mL maker you can CAREFULLY place the white/clear
marble into the beaker. DO NOT drop the marble to the bottom of the graduated cylinder,
because it could break the graduated cylinder. You can then record the change in water level.
34
You can then CAREFULLY remove the marble from the graduated cylinder by pouring the
water and marble into your 50 mL beaker. To extract the marble you may use tweezers. You will
need to do the same procedure four more times (this will give you five trials). Make sure to dry
your marble between trials; otherwise your volumes will be incorrect, because you are adding
extra water with your marble. You will then need to repeat the procedure for the silver marble;
again making sure you do five trials. Once you have done that you will need to take the weight of
your marble. The weigh boat is to help ensure the marble doesn’t roll off the balance. Thus, you
will need to determine the weight of the weigh boat first. Then the weight of the marble and
weigh boat. Once you have those numbers you will need to calculate the weight of the marble by
itself. Once you have all your information, you can clean up and start your data processing
portion.
Safety:
In this lab you will need to wear, goggles, closed toed shoes, and lab coats. Since you will be
working with glass you will need to ensure the safety of your body and eyes. DO NOT lose any
materials especially the marbles. Throwing marbles or being carless with them is grounds for
expulsion from the lab. Any long hair will need to be tied back to ensure it does knock anything
over.
Environmental Safety:
There is very little environmental concerns for this lab. Any dangerous particulates that are being
transferred from the marbles to the water will be highly diluted within the water. Thus when the
water goes down the drain, the environment see little to no change.
Data Collection:
Marble Volume Change
Volume Change
Trial 1 Trial 2 Trial 3 Trial 4 Trial 5 Average
Marb
les
White/Clear
Silver
Marble Mass Values
Mass (g)
Weigh Boat
Weigh Boat and White/Clear Marble
White/Clear Marble
Weigh Boat and Silver Marble
Silver Marble
Data Processing:
1. Create a bar graph that shows the averages of the volume change for the white/clear and
silver marble.
35
2. Determine the density in g/mL of the white/clear marble by using the weight of the
white/clear marble and the average volume change for the white/clear marble.
3. Determine the density in g/mL of the silver marble by using the weight of the silver
marble and the average volume change for the silver marble.
Challenge Questions:
1. What type of composition was the white/clear marble?
2. What type of composition was the silver marble?
3. Most if not all densities determined in a lab are never exactly on the stated value given.
Why does this occur?
4. Explain another way determine the composition of the marble without destroying the
marble.
Conclusion/Evaluation:
1. Write your own conclusion and evaluation of this lab.
36
“Beanium” Lab
Background:
Most elements on the Periodic Table exist in at least two isotopic forms. Isotopes are
atoms with the same atomic number but with different mass numbers due to varying numbers of
neutrons. The atomic mass shown on the Periodic Table for each element, is actually an average
of all the isotopes of that element, weighted by the percentage of the abundance in which they
occur.
NEWS FLASH!!! A NEW ELEMENT HAS BEEN DISCOVERED.
Springfield USA—Nuclear Chemists, performing basic research on food products at Springfield
Power Plant, have discovered what is believed to be a new element. Mr. Burns, the plant’s
owner, says, “We have tentatively named this element Beanium.” Mr. Smithers, assistant to Mr.
Burns adds, “We derived this element from the protein nodules we put into our chili.”
Further research of the new element will be conducted in more
suitable surroundings, namely laboratories in a nearby school. Because
Springfield apparently only has an elementary school, research work
has been contracted to neighboring Clayton High School. “Student
excitement regarding this discovery is running at a fever pitch!” says
Lisa Simpson, student. Many chemistry students have generously
volunteered their time and expertise to help with the follow-up
experiments involving the new element.
Dr. Julius Hibbert says the first follow-up experiments
conducted at Clayton High School will determine how many isotopes
of this element exist. The second experiment will determine the mass
of each isotope. The third experiment will determine the percent
abundance of each isotope. The final calculations will discover the
average atomic mass of the new element.
“One unique property of Beanium should make these experiments particularly easy—
unlike normal atoms, Beanium atoms are very large.” says Mr. Smithers. “They can be easily
seen, and different isotopes can be sorted by hand.”
Scientists are expecting a complete, comprehensive summary of this new element within
two days, including diagrams and collected data tables. “This is the most exciting Chemistry
discovery this century!” exclaimed Mr. Burns.
Objective:
Be able to calculate the amu for beanium.
Materials:
Cup of beans
Triple balance beam
Calculator
Methods:
In this lab your group will be given a cup of beans, which is a representation of all the beanium
isotopes, which exist in nature. Careful, each group has been given different number of beans,
thus no two groups will have the same amu for beanium. Organize your beans, calculate the
37
percentage of each type of bean you have been given; then determine the amu for your beanium
cup.
Safety:
All items for this experiment are natural products. However, they have been exposed to a
chemical environment. Thus, consumption of the beans is prohibited. No lab coat or safety
googles are required for this lab. Closed toed shoes are required, in case a triple balance beam is
dropped. Moreover, throwing any beans around the lab room is grounds for expulsion from the
lab.
Environmental Safety:
There is no environmental safety for this lab, since we will not be disposing of any component of
this lab.
Data Recording:
Total # of beanium atoms in sample ____________
In the table below, draw a picture of the Location and Shape of Object:
Isotope # of atoms of
this isotope
present
Total mass of all
the atoms of this
isotope
Average mass of
this isotope
(Show
calculation in
data processing)
% abundance of
this isotope
(Show
calculation in
data processing)
Whitebeanium
Blackbeanium
Redbeanium
Pintobeanium
(has brown
spots)
Data Processing:
1. Calculate the average mass of each isotope. Remember to record your answers into the
table above and to show all your work.
2. Calculate the percent abundance of each isotope. Remember to record your answers into
the table above and to show all your work.
Challenge Questions
1. Explain why how you could have estimated the amu of your beanium cup before you did
any calculations but after sorting?
2. Explain how another isotope would effect your calculations if it had a percent abundance
of 25%?
Conclusion/Evaluation:
1. Create your conclusion and evaluation of this lab.
38
Spectrophotometry Lab
Background:
We see very differently than we hear. With sound, we are able to pick out many different
frequencies, i.e. different pitches. For example, if we listen to music, we can pick out the drums
and voice separately, even though they are happening at the same time. We don’t have that
capability with light. Instead, we end up seeing one individual color, which most likely is made
up of many different wavelengths of light. The electromagnetic spectrum, shown in Fig. 10.1,
covers a huge range of wavelengths, from gamma rays at 10−14 m to AM radio waves at 104 m.
In this lab we are going to be concerned with the narrow band of wavelengths, ∼ 400 − 750 nm
(a nm = 10−9 m), that make up visible light. In order to know very accurately what wavelengths
are being emitted by a source of light, we will use a digital spectrometer.
Figure 10.1: The electromagnetic spectrum with the visible light region blown up.
Objective:
You will be able to determine the atomic emission spectrum of different lights.
Materials:
Lab book
Calculator
Methods:
In this lab you will be using a spectrophotometer to see the different types of light in which
various light sources give off. Since we do not have an excess amount of light sources, this lab
has been set up as lab stations. Each lab station has space in which you can look at the various
light sources with its own spectrophotometer. DO NOT REMOVE SPECTROPHOTOMETERS
FROM ITS STATION. The light sources you will look at will be sun light, a light bulb, a heat
lamp, and a neon light. Your group will rotate around the four different stations to see and collect
your data. Be aware you will be sharing the stations with your classmates, so please do not move
39
anything in the stations. Furthermore, please move through the stations quickly so that everyone
has a chance to see each station.
Safety:
As you know many different light sources can be harmful to our retinas (a component of our
eyes which enables us to see). Hence, staring at any light source or an extended period of time
can be very harmful. The spectrophotometer is designed to help separate the light into its various
colors, and ensure we are not directly looking at the light source. However, you will still need to
ensure you stare no longer than 30 seconds at any of the light sources in the lab. Furthermore,
since you will need your eyes inhibited (vision blocked) during this lab, you will not need to
wear goggles. A lab coat will also not need to be worn, since you are not working with
chemicals. However, the heat lamp can become very hot. Do Not touch or play with the heat
lamp in any way. Clothing, paper, or spectrophotometer to close to the heat lamp, could catch on
fire, so be sure to stand at least an arm distance away from the lab. Furthermore, do not move,
touch or disrupt any station, since they have been previously prepared for you class, and will be
used in other classes.
Environmental Safety:
The components of light sources can be dangerous to the environment if not disposed of
properly. Luckily much of the components that make up lights can be recycled and reused. Thus,
all light sources will be recycled for the environment.
Data Collection:
Light Source Colors Seen Corresponding
Wavelengths (nm) Observations
Sun Light
Lamp
Heat Lamp
Neon Light
Data Processing:
1. Using Figure 10.1 from the background calculate the frequency at which each light
source gives off. Remember there can be more than one color seen, thus you will need to
calculate every color seen. Show all your work.
Challenge Questions:
1. Explain how wavelength and frequency are related?
2. Explain how wavelength/frequency and energy are related?
3. Which light source gave off more energy? Does this make sense? If so explain, if not
explain.
Conclusion/Evaluation:
1. Write your own conclusion and evaluation for this lab.
40
Flame Test Lab
Background:
A Bunsen burner, named after Robert Bunsen, is a common piece of laboratory
equipment that produces a single open gas flame, which is used for heating, sterilization, and
combustion. The gas can be natural gas (which is mainly methane) or a liquefied petroleum gas,
such as propane, butane, or a mixture of both. The hose barb is connected to a gas nozzle on the
laboratory bench with rubber tubing. The gas then flows up through the base through a small
hole at the bottom of the barrel and is directed upward. There are open slots in the side of the
tube bottom to admit air into the stream via the venturi effect, and the gas burns at the top of the
tube once ignited by a flame or spark. The most common methods of lighting the burner are
using a match or a spark lighter.
The amount of air mixed with the gas stream affects the completeness of the combustion
reaction. Less air yields an incomplete and thus cooler reaction (orange flame), while a gas
stream well mixed with air provides oxygen in an equimolar amount and thus a complete and
hotter reaction (blue flame). The air flow can be controlled by opening or closing the slot
openings at the base of the barrel, similar in function to the choke in a carburettor.
The hottest part of the flame is the tip of the inner flame, while the coolest is the whole
inner flame. Increasing the amount of fuel gas flow through the tube by opening the needle valve
will increase the size of the flame. However, unless the airflow is adjusted as well, the flame
temperature will decrease because an increased amount of gas is now mixed with the same
amount of air, starving the flame of oxygen.
Objective:
You will be able to determine the cation in an unknown solution.
Materials:
Two to three sticks of each metal solution
250 mL beaker
Methods:
Each solution and station has been prepared for all classes. DO NOT mix sticks around the stock
solution, as it will contaminate the solutions for other classes. Each stock solution will have
sticks soaking in them. You will need one stick from each stock solution. Make sure to keep
track of each stick, to ensure you know what metal is producing the particular color. You will
need a trash beaker for all your sticks. Using your 250 mL beaker place at least 50 to 100 mL of
Bunsen burner flames depend on air
flow in the throat holes (on the
burner side, not the needle valve for
gas flow): 1. air hole closed (safety
flame used for lighting or default), 2.
air hole slightly open, 3. air hole half
open, 4. air hole fully open (roaring
blue flame).
41
water to create a proper trash beaker for this lab. All Bunsen burners have been set up. When you
are prepared with all your sticks and trash beaker call Ms. Manakul over and she will light your
flame. Do not play around with the flame, as this will qualify as horseplay (leading to automatic
ejection from the lab). Once you have a medium heat flame, move the stick within the flame
until you see some color change. This may need to be done two to three times (with different
sticks). BE CAREFUL to not light the stick on fire. When you are done with the stick or in case
it catches fire, make sure to place the stick into your trash beaker – flame side into the water.
Once you have observed all metals, dry your sticks and thrown them away. To turn off the
Bunsen burner, turn off the gas first (at the source). Burner may stay out to cool for next class.
Clean trash beaker and place everything away.
Safety:
A Bunsen burner can produce a very hot flame. Thus, full lab gear (lab coat, goggles, and closed
toed shoes) should be worn at all times. Since flames will consume any food source it comes into
contact with, lab coat sleeves should be rolled (not pushed) up at all times. Pushed up sleeves can
fall down at any time, thus rolling sleeves is a better method of safety. Lastly, all used sticks
should be clearly no longer lit before being thrown away.
Environmental Safety:
Since the chemicals are burned clean from the test sticks, no chemicals are released to the
environment when the sticks are thrown away. However, the room will be well vented to ensure
that when the chemicals are vaporized (turned into a gas) are diluted, ensuring less harm to the
environment.
Data Collection:
Stick Main metal Color produced
Data Processing:
1. What is the metal in the unknown?
Challenge Questions:
1. Each solution produces a unique color. Would you expect this result based on the modern
view of the atom?
2. Some commercially available fireplace logs burn with a red and/or green flame. What
elements would be responsible for these colored flames?
3. Aerial fireworks contain gunpowder and chemicals that produce colors. What element
would you include to produce crimson red? Yellow?
Conclusion/Evaluation:
1. Write your own conclusion and evaluation for this lab.
42
Paper Chromatography of Food Dyes Lab
Background:
Paper chromatography is an analytical method used to separate colored chemicals or
substances. It is primarily used as a teaching tool, having been replaced by other chromatography
methods, such as thin-layer chromatography and gel electrophoresis. This is useful for separating
complex mixtures of compounds having similar polarity, for example, amino acids. The setup
has two components. The mobile phase is a solution that travels up the stationary phase, due to
capillary action (the ability of a liquid to flow through narrow spaces even against gravity). The
mobile phase is generally an alcohol solvent mixture, while the stationary phase is a strip of
chromatography paper, also called a chromatogram. The chromatogram is loaded with the
compound which is to be separated. The molecules which are smaller have the ability to move
more quickly through the chromatography paper. This can be quantified by the retardation factor
(Rf) value.
The retardation factor (Rƒ) may be defined as the ratio of the distance traveled by the
substance to the distance traveled by the solvent. Rƒ values are usually expressed as a fraction of
two decimal places.
𝑅𝑓 = 𝑑𝑖𝑠𝑡𝑎𝑛𝑐𝑒 𝑝𝑖𝑔𝑚𝑒𝑛𝑡 𝑚𝑜𝑣𝑒𝑑
𝑑𝑖𝑠𝑡𝑎𝑛𝑐𝑒 𝑠𝑜𝑙𝑣𝑒𝑛𝑡 𝑚𝑜𝑣𝑒𝑑
If Rƒ value of a solution is zero, the solute remains in the stationary phase and thus it is
immobile. If Rƒ value = 1 then the solute has no affinity for the stationary phase and travels with
the solvent front. To calculate the Rƒ value, take the distance traveled by the substance divided
by the distance traveled by the solvent (as mentioned earlier in terms of ratios). For example, if a
compound travels 9.9 cm and the solvent front travels 12.7 cm, (9.9/12.7) the Rƒ value = 0.779 or
0.78. Rƒ value depends on temperature and the solvent used in experiment, so several solvents
offer several Rƒ values for the same mixture of compound.
Food coloring, or color additive, is any dye, pigment or substance that imparts color
when it is added to food or drink. They come in many forms consisting of liquids, powders, gels,
and pastes.
Objective:
You will be able to infer differences in polarity by observing the separation of food dyes.
Materials:
Chromatogram paper
Sharpies – Black, Blue, and Red
250 mL beaker
Stirring rod
100 mL of Ethanol
Methods:
Obtain a precut chromatogram paper strip. Using a PENCIL
DO NOT USE A PEN (pens consist of similar dyes and
could affect your results, while pencils are made of graphite,
a non-polar molecule, and will not affect your results) draw
a line 1 mm from the bottom of the paper, as you see
represented by the dashed line in the picture to the right.
X X X Black Blue Red
43
Again with a pencil place the labels for the colors we will be using – as shown in the picture.
Where the X’s are (about 2 mm from the bottom of the strip), draw a small dot for each color.
Make sure the dots do not touch – this will make the colors blead and you will not get good
separation. Allow the spots to dry for a minute before continuing. Place the glass stirring rod
through the hole in the chromatogram paper strip; this will allow the strip to stand upright in the
250 mL beaker as seen in the picture below.
Gently pour enough ethanol into the 250 mL so that the top of the ethanol touches the first pencil
line (1 mm from the bottom of the strip); WHILE MAKING SURE NONE OF THE LIQUID
TOUCHES THE PAPER ANYWHERE ELSE!. Wait for the solvent to travel through the
chromatography paper (this will take several minutes). Once the solvent has reached the glass
stirring rod, take the chromatogram out and with a pencil mark a line indicating the distance
traveled by solvent. If you do not mark your end line, you will not know your measurements
after the chromatogram dries, which only takes a few minutes. Once you have collected your
data, you may throw the chromatography paper away, and the solvent may go down the drain
with lots of water.
Safety:
Sharpie dyes are designed to stain organic substances. Since people and clothes are made up of
natural/organic substances, you will need to wear full lab gear (lab coat, goggles, and closed toed
shoes). This is to ensure you don’t walk away very colored.
Environmental Safety:
Most sharpie dyes are made mostly from natural colors. Thus, the use and disposal of these dyes
will show little to no effect to the environment.
Glass stirring rod
44
Data Collection:
Black
Color Produced Distance solvent
traveled
Distance color
traveled
Rf (Remember to
show work in the
data processing
section)
Blue
Color Produced Distance solvent
traveled
Distance color
traveled
Rf (Remember to
show work in the
data processing
section)
Red
Color Produced Distance solvent
traveled
Distance color
traveled
Rf (Remember to
show work in the
data processing
section)
Data Processing:
1. Calculate the Rf values for each color for each pen. Remember to show all work and
place your answers in the correct columns in the data collection section.
2. Based on the Rf values, which dye is the most polar? Which dye is the least polar?
Challenge Questions:
1. Describe what would happen if we used a different solvent like water, vinegar, or
ammonia.
2. Describe what would happen if we used a different chromatogram substance like paper
towels and note-book paper.
Conclusion/Evaluation:
1. Write your own conclusion and evaluation for this lab.
45
Precipitation Lab
Background:
When doing these reactions involving ionic compounds remember they are made of
positive and negative ions held together by the attractive, electrostatic forces that occur between
oppositely charged particles. In water, soluble ionic compounds break apart completely into their
respective ions. Example: NaCl (s) when put into water yields Na+ (aq) and Cl- (aq), and AgNO3
also dissociates in water to form these respective ions Ag+(aq) and NO3-(aq). It turns out that
when these two solutions of sodium chloride and silver nitrate are mixed a solid falls out – a
process called precipitation. This is visually seen in small samples, when two clear solutions
mixed to form a cloudy or opaque looking solution.
Objective:
You will be able to write a set of rules for which compounds produce solid precipitates.
Methods:
On a separate piece of paper copy the grid shown below. Make sure to make the sizes match that
of your well plate. Place your well plate over the grid. Add one to two drops of each chemical in
their respective wells. Record your results in your data collection table/grid. When done
carefully rinse your well plate with lots of water.
AgNO3 (Ag+) Pb(NO3 (Pb+) CaCl2 (Ca2+)
Na2CO3 (CO32-)
Na3PO4 (PO43-)
NaOH (OH)
Na2SO4 (SO42-)
NaCl (Cl-)
Safety:
Since you are working with chemicals which can cause irritation to skin and lungs, full lab gear
(goggles, lab coat, and closed toed shoes) will be worn for the duration of the lab. Should you
come in contact with any of the chemicals, rise with lots of water and see Ms. Manakul for
further instructions.
Solution containing Solution containing Solution containing aqueous NaCl aqueous AgNO3 aqueous NaNO3 and
solid AgCl
46
Environmental Safety:
Since we are using small amounts for this lab, the reactants used and the products produced will
have little to no effect on the environment.
Data Collection:
Fill in the table with a description of what is produced when the two substances are
mixed.
AgNO3 (Ag+) Pb(NO3 (Pb+) CaCl2 (Ca2+)
Na2CO3 (CO32-)
Na3PO4 (PO43-)
NaOH (OH)
Na2SO4 (SO42-)
NaCl (Cl-)
Data Processing:
1. Write complete balanced chemical equations for each reaction. Remember to include
states of matter.
2. Based on this lab, how would you know which ions always created a solid and which
ones always didn’t?
Challenge Questions:
1. Of the balanced chemical equations you wrote in data processing, which one(s) are not
proper chemical reactions? Why would you consider these not proper chemical reactions?
Conclusion/Evaluation:
1. Write your own conclusion and evaluation for this lab.
Appendix
A
Flowchart for Naming Chemical Compounds
How many elements are in the
compound?
Is the first element a metal? Does the formula begin with
NH4?
Two Three or more
The compound is ionic.
Does it contain a transition
metal?
The compound is
covalent. Use the
prefixes to name the first
element (except don’t use
mono- for the first one),
then use the prefixes to
name the second element as
well.
The compound name begins
with ammonium.
Name the metal, then
name the polyatomic
anion using your list. Don’t
change any parts of the
names.
Yes
No
Yes No
How many elements are left
after NH4?
Name the non-metal element, but
change its ending to –ide. The
compound name is ammonium
something-ide.
Name the polyatomic anion. Don’t
change any parts of the name. The compound
name is ammonium something.
One Two or more Name the
metal, then
name the non-
metal, but
change its
ending to
–ide.
Name the metal,
give the charge as a
Roman
numeral in
brackets, then name
the non-metal,
but change its
ending to –ide.
No
Yes
END
END
END
END
END
START
END
B
Flowchart for Writing Formulas for Chemical Compounds
Yes
Does the name contain
prefixes?
Is the first name
ammonium?
The compound is
covalent. Write the
symbol for each element
and use the prefixes to find
the subscripts.
No
Yes
The compound is ionic.
Does the name contain a
Roman numeral?
The compound is ionic and
contains NH41+. Is the
anion name on the list of
polyatomic anions?
No Yes
Determine the charge of the
cation from the periodic table (the
group number).
Use the charge of the polyatomic anion
with the charge of the cation to
balance the charges.
No Yes
The Roman numeral
gives the charge on the
metal ion. Use this
when balancing the
charges.
Is the anion name
on the list of
polyatomic ions?
No
Yes
END
END
No
Write the formula using
subscripts to show how many of
each ion are needed to balance
the charges.
Find the charge of the anion using the periodic
table and use this with the cation charge to
balance the charges. You can draw Lewis dot
(electron transfer) diagrams if you like.
START
C
VESPR Theory
Species Type Geometry Shape Bond Angle Example
A2 Linear Linear 180° H2
AX2 Linear Linear 180° CO2
AX3 Planar
Triangular
Planar
Triangular 120° BF3
AX2E1 Planar
Triangular V-Shape 104.5° SO2
AX4 Tetrahedral Tetrahedral 109.5° CH4
AX3E1 Tetrahedral Pyramidal 109.5° NH3
AX2E2 Tetrahedral V-Shape 104.5 H2O
AX5 Triangular
Bipyramidal
Triangular
Bipyramidal
90°, 120°,
180° PCl5
AX4E1 Triangular
Bipyramidal See Saw
90°,
120°¸180° SF4
AX3E2 Triangular
Bipyramidal T-Shape 90°, 180° ClF3
A3E3 or
AX2E3
Triangular
Bypiramidal Linear 180° I3
-
AX6 Octahedral Octahedral 90°, 180° SF6
AX5E1 Octahedral Square
Pyramidal 90°, 180° BrF5
AX4E2 Octahedral Square Planar 90°, 180° XeF4
D
MOLE MAP
Representative particles (Atoms, molecules, ions use Avogadro’s
number)
MASS (Use average atomic mass off of the
periodic table or GFM by adding all
atomic masses in formula together to
calculate the molar mass)
Volume of a GAS Used only for gases
@ STP
MOLE ALL MOLE RATIOS ARE DONE
HERE
6.022 x 1023 rep part 1 mole
1 mole 6.022 x 1023 rep part
Molar mass g 1 mole
1 mole molar mass g
22.4 L 1 mole
1 mole 22.4 L
Volume of a solid, liquid or gas (Use density)
Density= MASS VOLUME
1 = VOLUME Density MASS
Volume of a Solution (Use Molarity = M)
X mole solute 1 L of solution (aq)
1 L of solution (aq) X mole solute