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C h a p t e r 1 C h e m i s t r y 1 A P a g e | 1
Beginning:
Materials: Chemistry: A Molecular Approach, Tro, 4th edition, Pearson, 2017,
Chem 1B Lab Manual, Dept. of Chemistry at Moorpark College,
Safety Glasses, and Scientific Calculator with exponential and logarithmic
functions (no cell phones, graphing, programmable, alpha typing calculators
allowed during tests/quizzes) MasteringChemistry access code (access to
online assignments, e-book, tutorials, powerpoints, etc.)
How to start: Review the math found in Appendix. If the math in Appendix is difficult to
follow, consider taking more algebra before attempting Chemistry 1A. It is
expected that students in Chemistry 1A have a background in chemistry;
therefore the material is covered quickly and intensely. Read, study and work
problems often and regularly to keep up. Look over materials and websites.
Notice the appendices I-IV and glossary in the textbook as well as resources
in MasteringChemistry. We cover Chapters 1-13 in Chemistry 1A. When
starting a new Chapter read the contents (section titles) found on the first page
of the chapter, chapter in Review at the end. After you have a general
overview of the upcoming material read the chapter text before coming to
lecture and a second time after the material is covered in lecture. Work out
the examples and problems and work a variety of the end of chapter
homework problems for practice and greater understanding.
Syllabus: Refer to the syllabus often to know the class expectations, laboratory
activities (experiments, formal lab write-ups, and workshops), test days, etc.
More help: Your instructor has office hours set aside each week for assistance. The
learning center in the library often has tutors that may help in math and chemistry. It
is recommended that you exchange co Look over the lab assignment before attending
the labs
ntact information with others in the class to assist in forming study groups, assist with
getting a ride to school when your car does not work, having someone to ask
a question regarding class, or after missing a class to find out what was
covered.
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Chapter 1: Matter, Measurement and Problem Solving
Homework:
Read Chapter 1 and work out sample/practice exercises and end of chapter problems
for more practice.
Look over the lab assignment before attending the labs
Memorize the names (correct spelling) and symbols (capitalize only the first letter)
of the 44 common elements in the handout.
Register for and start the homework online through MasteringChemistry
Chemistry: The science that seeks to understand the behavior of matter by studying the
behavior of atoms, molecules and compounds. The study of the composition, properties,
and transformations of matter.
Matter: Anything that has mass and occupies space. Matter is composed of atoms,
molecules, and compounds
Atoms and Molecules: Matter, composition, structure, element, atom, molecule,
compound; chemical bonds. All things are made of atoms.
This image shows the Kanji for
“atom” written with
individual Fe atoms on top of Cu
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The Scientific Method: A systematic procedure for solving problems and exploring
natural phenomena. Chemists employ the scientific method, which makes use of
observations, hypotheses, laws, theories, and experiments.
Observations (data; a series of measurements or observations)
o observations are the foundation of the scientific method
o Some observations are made with the naked eye, while others rely on
instrumentation.
o data can be qualitative descriptions or quantitative measurements.
o Scientific data may be graphed to see relationships.
o data is most useful when collected under controlled conditions, experiments
Hypotheses
o tentative explanations to interpret the observations
o a useful hypothesis must be testable
o must be rejected or corrected when they conflict with experiment
Experiments
o experiments must be repeatable and reproducible
Practical use of the Scientific Method…
Observation/Problem:
The lamp in the bedroom will not light/turn on.
Possible hypotheses:
Come up with some testable hypothesis from your experience
Experiments:
From each hypothesis, an experiment can be conducted to test the
hypothesis/explanation. More observations are obtained through experiments
and over time, a good hypothesis/explanation is repeatable and reproducible.
What experiments can be performed to check your hypothesis?
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The cycle of the scientific method is repeated many times with rejections, alterations,
improvements and support. Numerous observations and experiments lead to Scientific
Laws and Theories.
Scientific Laws come from observations (also called natural laws)
compactly summarize patterns and results of a large number of observations
predicts future observations
may apply only under special conditions
are descriptions of nature that predict future outcomes, not explanations
A few examples of Natural Laws(also known as Scientific Laws or just Laws)…
1. Newton’s Laws of Motion
2. Dalton’s Law of Partial Pressures
3. Lavoisier’s Law of Conservation of Mass
Scientific Theories come from hypotheses
Are well-tested models that explain and give the underlying causes for
observations and laws.
Discarded or refined when they can't explain new experimental results
A good theory...
explains currently available data
is as simple as possible (but no simpler!)
accurately predicts results of future experiments
suggests new lines of work and new ways to think
clearly shows underlying connections
A few examples of Theories…
1. Heliocentrism (1543, Copernicus)
2. Evolution (1859, Darwin)
3. Quantum Theory (Max Planck, Einstein, Niels Bohr, Werner Heisenberg,
Erwin Schrödinger, Max Born, Paul Dirac, 1900–1926)
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The Scientific Method (Do you understand it?)
1. A number of people become ill after eating dinner in a restaurant. Which of the
following statements is a hypothesis?
a) The cooks felt really bad about it.
b) Bacteria in the oysters may have caused the illness.
c) Everyone who ate oysters got sick.
d) Symptoms include nausea and dizziness
e) People got sick whether the oysters were raw or cooked
2. The Scientific Method
a) is just a theory
b) is a strict set of rules and procedures that lead to inarguable fact.
c) isn't used much in modern chemistry.
d) is based on continued observation and experiment.
e) is a framework for proving an argument you know to be true.
3. Which of the following statements is TRUE?
a) A scientific law explains an observation.
b) Once a theory is constructed, it is considered fact.
c) A hypothesis is speculation that is difficult to test.
d) An observation explains why nature does something.
e) A scientific law summarizes a series of related observations.
4. Classify each of the following as an observation (O), a law (L), or a theory (T)
_____ a) Matter is made of atoms
_____ b) Matter is conserved in chemical reactions
_____ c) When wood burns in a closed container, its mass does not change
_____ d) A body in motion stays in motion unless acted on by a force
_____ e) The universe began as a cosmic explosion called the Big Bang
_____ f) A stone dropped from 450 meters falls to the ground in 9.6 seconds.
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Element: A fundamental substance that cannot be chemically changed or broken down
into anything simpler. All elements are made from stardust.
About 90 are naturally occurring. 75% of the observed mass of the universe is H
Percentage of Elements by Mass in the Earth
Percentage of Elements by Mass in the Human Body
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Memorize the names (correct spelling) and symbols (capitalize only the first letter) of the
44 common elements in the handout.
Historical Notes: pottery and ceramics, glass, embalming, bronze age, metals,
Chinese (Yin, Yang), Greek (Earth, Wind, Fire, Water, Ether), alchemy, scientific method.
Periodic Table:
1789 French scientist Antoine Lavoisier first tabulated the known elements (24)
1829 Johann Dobereiner observed triads (Ca, Sr, Ba and Cl, Br, I and Li, Na, K), by
1843, sixteen triads were known.
1869 Russian chemist Dmitri Mendeleev placed elements in 7 horizontal rows
(Periods) and 18 vertical columns (Groups). Elements in a group behaved
similarly.
Main groups, transition metals, inner transition metals(rare earth metals)
Alkali metals, alkaline earth metals, halogens, noble gases
Metals, semimetals (metalloids), nonmetals
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The Study of Chemistry:
Chemistry: The study of the composition, properties, and transformations of
matter.
1. Atomic and Molecular Perspective- Matter, composition, structure, element, atom,
molecule, compound,
2. Why Study Chemistry –Chemistry provides important understanding of our
world/universe and how it works. It is a very practical science that has improved
our daily lives. It is the foundation that provides the basic language required for
many other science and technological fields.
Classifications of Matter:
States of Matter:
solid liquid gas
Properties: (shape, volume, energy content, phase changes, endothermic vs.
exothermic).
Solids may be crystalline or amorphous
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Pure Substances Pure substances have one invariable composition independent of how they
were formed.
elements (memorize the common elements and symbols for quiz)
molecules
compounds.
Mixtures:
Mixtures have a variable composition
Heterogeneous: composition varies from one region to another
Homogeneous: uniform composition
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Separation Mixtures:
Different components have different physical or chemical properties which enable
separations.
Distillation:
Evaporation:
Decanting:
Filtration:
Chromatography: paper, liquid, gas
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Properties of Matter:
1. Physical: A property or
change that does not change
the chemical composition
such as… change of state,
separation of mixtures
(decantation, filtration,
evaporation, distillation,
chromatography),
temperature, odor.
2. Chemical: A property or change that does
involve a change in the chemical makeup such
as… Elements to compounds, reactants forming a
different compound, change in chemical structure
and composition, rusting (oxidation of metals),
combustion, and decomposition.
3. Intensive: Property is independent of the
amount… density, melting point, color
4. Extensive: Property is dependent of the
amount… mass, volume, and length
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Energy: Energy is the capacity to do work. Work is force applied across a distance,
push or pull on an object.
Energy can be converted from one form to another. When matter undergoes a
chemical or physical change, the amount of energy in the matter also changes.
Potential energy
Kinetic energy
Thermal energy is a form of
kinetic energy as the molecules
are moving.
Law of Conservation of Energy
Spontaneous processes prefer the direction that will lower energy
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Units of Measurement:
SI Units (Systeme International d’Unites) chosen by international agreement in
1960 based on the metric system.
Physical Quantity Unit Abbreviation
Mass kilogram kg
Length meter m
Temperature Kelvin K
Amount mole mol
Time second s
Electric current ampere A
Luminous intensity candela cd
Volume (derived unit), dm3 liter L
Density (derived unit), mass/V kg/m3 Solid, liquid: g/cm3=g/ml,
for gases: g/L
Energy (derived unit), kgm2s-2 joule J
Prefixes used in the metric system.
Prefix Abbrev. Meaning Example
Giga G 109 1 Gigabyte = 1 x 109 bytes
Mega M 106 1 Megameter = 1 x 106 meter
kilo k 103 1 km = 1 x 103 m
unit - 1 1
deci d 10-1 10 dm = 1 m
centi c 10-2 102 cm = 1 m
milli m 10-3 103 mm = 1 m
micro 10-6 106 m = 1 m
nano n 10-9 109 nm = 1 m
pico p 10-12 1012 pm = 1 m
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Know these Common Conversions. (more in textbook)
Length 2.54cm = 1 inch 1 km = 0.621 mi
Mass 453.6 g = 1 pound (lb) 1 kg = 2.205 pounds (lbs)
Volume 1 ml = 1 cm3 = 1 cc 946 ml = 1 qt
Temperature °C = K -273.15
K = (°C) + 273.15
°F = 1.8(°C) + 32
°C = [(°F) – 32]
1.8
Energy 4.184 J = 1 calorie 1.602 x 10-19 J = 1 eV
Temperature:
Derive the temperature
conversion formulas:
y = mx +b
Choose x as Celsius to have a
simple y intercept (b)
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Uncertainty in Measurement:
Inexact (has uncertainty)
Exact (definitions: i.e. 1 ft = 12 in, or
whole items: i.e. number of
students enrolled)
Precision (measurements agree with
each other)
Imprecision in measurements may be
caused by random or systematic
errors.
Random error (no specific cause, cannot
be corrected)
Systematic error (caused by limitations
in technique, experimental design,
or instrument calibration, can be reduced)
Accuracy (measurement agrees with true value)
Significant Figures-only the last digit is estimated/uncertain.
What is your estimated reading for the graduated cylinder?
Rules for significant figures:
Exact numbers Unlimited
significance
1000mm = 1 m
Numbers 1 through 9 Significant 25.223 g
Leading zero Never significant 0.00402 kg
Captive zero between nonzero Significant 2.005 x 108 atoms
Trailing zero with decimal Significant 3.200 x 104 s
Trailing zero without decimal Uncertain 1400 miles
Significant Figures in Calculations:
1. Addition and Subtraction-minimum significant to the right taken
2. Multiplication and Division-least number of significant numbers
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Rounding Numbers:
Remove all nonsignificant numbers. Less than 5 round down (drop it), when 5 or
more round up.
Scientific Notation: When writing very large or very small values it is best to remove the
placeholder zeroes and keep all the significant numbers. Scientific notation keeps one
digit before the decimal, remaining significant figures after the decimal, and multiplies by
a factor of ten (negative power for small munbers and positive for large numbers.
?.??? x 10?
12,300,000 min = 1.23 x 107 min 0.000 000 000 765 m = 7.65 x 10-10 m
Dimensional Analysis:
Aids problem solving using conversion factors/definitions
1. Always write every number with its unit
2. Always include units in calculations
3. Use conversion factors to generate equivalence statements
4. Arrange conversion factors to cancel starting units
5. May string conversion factors together
6. When squaring a conversion factor one must square both the number and unit, When
cubed, number and unit must be cubed
7. Round off at the final step, do not round progressively
8. Sort, Strategize, Solve, Check
Practice Problems:
1. One lead has a mass of 0.000 000 000 000 000 000 000 3441 g. Express this in
proper scientific notation.
2. Indicate the number of significant figures in each and write in Scientific Notation.
a) 0.000343 km
b) 645,000,000 ml
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3. Convert 8.22 x 102 nanoliters/min into units of quarts/year.
4. The average surface temperature of the South Pole is -56C.
a) What is this temperature in Kelvin?
b) What is this temperature in Fahrenheit?
5. A student finds that the weight of an empty beaker is 53.583 g. She places a solid in
the beaker to give a combined mass of 57.483 g. To how many significant figures is
the mass of the solid known?
6. A 3.00 quart container weighs 302 grams when empty. When it is filled with liquid,
the container weighs 2.412 kilograms. What is the density of the liquid in g/ml?
7. Describe the difference between experimental data which is accurate and data which
is precise. Give examples. What is the difference between random and systematic
errors?
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8. Place a P before a physical property or change and a C before a chemical property
or change:
The reaction with zinc and hydrochloric acid to produce a gas
Crystallization of CuSO4 by evaporation of its aqueous solution
Metals are shiny, malleable, ductile, good conductors of heat and electricity
Alkali metals combine with halogens in a 1:1 ratio to form a compound
9. For the following identify each in as many ways as possible using the following:
a) matter, b) pure substance, c) compound, d) molecule, e) element
f) homogeneous mix g) heterogeneous mix h) metal i) nonmetal
j) ionic compound k) alloy n) none
a) Oxygen, O2
b) Sodium bromide, NaBr
c) Cu-Zn alloy called brass
d) Burrito
e) Potassium
f) Hypothesis
10. Monel metal is a corrosion-resistant copper-nickel alloy used in the electronics
industry. A particular alloy with a density of 8.70 g/cm3 and containing 0.024%
silicon by mass is used to make a rectangular plate that is 30.0 cm long, 17.0 cm
wide and 3.00 mm thick.
What is the volume of the alloy?
What is the mass of the alloy?
What is the mass of just the silicon in the sample?
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Practice Problems: (ANSWERS)
1. 3.441 x 10-22 g
2. a) 0.000343 km 3.43 x 10-4km
b) 645,000,000 ml 6.45 x.108 ml
3. 0.457 quarts/year.
4. a) 217 Kelvin
b) -69 ˚F
5. 3.900 g; answer has 4 significant figures
6. 0.743 g/ml
7. Precision (measurements agree with each other). Accuracy (measurement agrees
with true value). You may want to check the weight of a suitcase so you will not be
charged extra for too much baggage before going on an airline flight. You may
weigh your suitcase on the same bathroom scale several times and find the numbers
agree with each other (precision). If the bathroom scale always reads 5 pounds
lighter that the true value you will not be accurate and possible pay the extra fee.
That bathroom scale has a systematic error that may be fixed with calibration.
8. C The reaction with zinc and hydrochloric acid to produce a gas
P Crystallization of CuSO4 by evaporation of its aqueous solution
P Metals are shiny, malleable, ductile, good conductors of heat and electricity
C Alkali metals combine with halogens in a 1:1 ratio to form a compound
9. a) Oxygen, O2 a, b, d, e, i
b) Sodium bromide, NaBr a, b, c, j,
c) Cu-Zn alloy called brass a, f, k
d) Burrito a, g
e) Potassium a, b, e, h
f) Hypothesis n
10. a) 153 cm3 volume
b) 1330 g mass alloy
c) 0.32 g mass of just the silicon