SHS Chemistry
September 2014
Mrs. Kaiser
Chapter 1, 2 and 3
Introduction to Chemistry, Matter and Change and
Scientific Measurement (Section 3.1,3.4)
Homework:
Due Friday (9/5) Pg 61 standardized test prep and vocabulary for chapter 1,2, and 3 (at
the end of this packet) sent using engrade to TURN IN.
Due Monday(9/8) On-line Quest Homework Assignment 1 Significant Figures or
alternate assignment.
Due Tuesday (9/9) Section 3.4 – Density, Read 3.4, p.93, Ques. 52,53,54,55,56 submit
using engrade to TURN IN
Labs and Activities: Lab Safety and Equipment, Hand Boiler Distillation, Ice Cube Lab, Recycling Factory,
Chromatography, Sig Fig Lab and Activity
Lab questions and/or reports/additional worksheets may need to completed as
homework.
Test 1,2,3: TBA(ask what 5 a day means), lab safety quiz before Friday, 9/5/2014
Chapter 1
Chemistry is the study of the composition of matter and the changes that matter
undergoes. Because living and non-living things are made of matter, chemistry affects
all aspects of life and natural events.
Chemistry explains our natural world, can prepare you for a career and helps you to be an
informed individual. Chemists:
 Design materials to fit specific needs,
 Play an essential role in finding ways to conserve energy, produce energy and store
energy,
 Discover medicines, materials and technology that doctors use to treat their patients,
 Help to develop more productive crops and safer, more effective ways to protect
crops,
 Help identify pollutants and prevent pollution,
 Gather data from afar and analyze matter that is brought back to Earth.
Thinking Like a Scientist
The word chemistry comes from alchemy. Long before there were chemists, alchemists
were studying matter. Alchemy arose independently in many regions of the world. It
was practiced in China and India as early as 400 b.c.
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Mrs. Kaiser
Practical Alchemy focused on developing techniques for working with metals, glass and
dyes. Mystical alchemy focused on concepts like perfection. _______ was seen as
perfect metal, alchemists were searching for a way to change other metals, such as lead
into gold. Although alchemists did not succeed in this quest, the work they did spurred
the development of chemistry.
Alchemists developed the tools and techniques for working with chemicals. They
designed equipment that is still used today. For example, beakers, flasks, tongs, funnels
and the mortar and pestle. What they did not do was provide a logical set of explanations
for the changes in matter that they observed. That task was left for chemists to
accomplish.
An Experimental Approach to Science
In France, Antoine-Laurent Lavoisier did work in the late 1700s that would
revolutionize the science of chemistry. Lavoisier helped to transform chemistry from a
science of observation to the science of ____________________ that it is today (He
designed a scale that could measure mass to the nearest 0.0005 gram)
He also settled the debate of why materials burn.
The Scientific Method
The scientific method is a logical, systematic approach to the solution of scientific
problem. You can think of the scientific method as the common sense method.
The steps of the scientific method are:
 Making Observations,
 Testing Hypotheses- a hypothesis is a proposed explanation for the observation,
 Performing Experiment – an experiment is a procedure that is used to test a
hypothesis. The variable you change during an experiment is the independent
variable. The variable that is observed during the experiment is the
_________________________ or the outcome measurement. For the results of the
experiment to be accepted it must be repeated many times with the same results (from
many different scientists),
 Developing Theories- Once a hypothesis meets the test of repeated experimentation ,
it may be raised to a higher level of ideas. It may become a theory. A theory is a
well tested explanation for a broad set of observations,
 Scientific Laws – a scientific law is a concise statement that summarizes the results
of many _____________________ and ____________________.
Chapter 2
Properties of Matter
Properties used to describe matter can be classified as extensive or intensive.
Extensive Properties-is a property that depends on the amount of matter in a sample
Mass of an object is a measure of the amount of matter the object contains.
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Mrs. Kaiser
Volume of an object is a measure of the space occupied by an object
Intensive Property- is a property that depends on the type of matter in a sample, not the
amount of matter.
Identifying Substances
Substance – matter that has a uniform and definite composition
Every sample of a given substance has identical intensive properties because every
sample has the same composition. For example, Gold and copper have some properties
in common, but there are differences besides their distinctive colors. Pure copper can
scratch the surface of pure gold because copper is harder than gold. Copper is a better
conductor of heat and electricity than gold. Copper and gold are malleable(they both can
hammered into sheets without breaking). But gold is more malleable than copper
Hardness, color , conductivity and malleability are examples of physical properties.
A physical property is a quality or condition of a substance that can be observed or
measured without changing the substance’s composition.
Substance
Neon
Oxygen
Chlorine
Ethanol
Mercury
Bromine
Water
Sulfur
Gold
Copper
Physical Properties of Some Substances
State
Color
Melting Point
Gas
Colorless
-249
Gas
Colorless
-218
Gas
Green
-101
Liquid
Colorless
-117
Liquid
Silvery-white
-39
Liquid
Reddish-brown -7
Liquid
Colorless
0
Solid
Yellow
115
Solid
Yellow
1064
Solid
Reddish yellow 1084
Boiling Point
-246
-183
-34
78
357
59
100
445
2856
2562
States of Matter
We will look at three states of matter in chemistry, solids, liquids and gases.
A solid has definite shape and volume. It is difficult to squeeze a solid into a smaller
volume. In addition solids only expand a little bit when heated.
A liquid is a form of matter that has an indefinite shape, flows, yet has a fixed volume.
Liquids are almost incompressible, but they tend to expand slightly when heated.
A gas is a form of matter that takes both the shape and volume of its container. The
words vapor and gas are used interchangeably but there is a difference. The term gas is
used for substances, like oxygen, that exist is the gaseous state at room temperature.
Vapor describes the gaseous state of substance that is generally a liquid or solid at room
temperature like chocolate or gallium.
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Physical Changes
During a physical change, some properties of a material change, but the composition
of the material does not change. Boil, freeze, melt and condense as well as break, split,
grind, ct and crush. Physical changes can be classified as reversible or irreversible.
Melting is an example of reversible physical change. Cutting hair and cracking an egg
are examples of irreversible physical changes.
Mixtures
A mixture is physical blend of two or more components. For example chicken soup and
air are example of mixtures. Soup is easy to see as a mixture. But remember air is a
mixture of gases.
Based on the distribution of their components, mixtures can be classified as
heterogeneous mixtures or as homogeneous mixtures.
Heterogeneous mixture – a mixture in which the composition is not consistent
throughout ex. Chicken soup
Homogeneous mixture – is a mixture in which the composition is uniform throughout.
Another name for this is a solution. Many solutions are liquids but some are gases, ex
air. Others are solids, like steel ( iron, chromium and nickel).
The term phase is used to describe any part of a sample with uniform composition and
properties. By definition, a homogeneous mixture consists of a single phase. A
heterogeneous mixture consists of two or more phases. When oil and vinegar are mixed,
they form layers
Separating Mixtures
Differences in physical properties can be used to separate mixtures.
Filtration is the process that separates a solid from a liquid
ex. a colander is used to separate pasta from water.
Distillation is a process where a liquid is boiled to produce a vapor that is then
condensed into a liquid. For example the impurities in tap water can be removed by
distillation. The solid substances that are dissolved in the water will remain behind in the
distillation flask because their boiling points are much higher than the boiling point of
water.
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Mrs. Kaiser
Elements and Compounds
Element is the simplest form of matter that has a unique set of properties. Oxygen and
hydrogen are of two of the more than 100 known elements.
Compound (from Latin to put together) is a substance that contains two or more
elements chemically combined in a fixed proportion. For example carbon, hydrogen and
oxygen are combined into the compound sucrose or table sugar.
Sucrose is the common chemical name for table sugar. Sucrose is a disaccharide; each
molecule of sucrose consists of two "simple sugars" or monosaccharides.
Compounds can be broken down into simpler substances by chemical means, but
elements cannot.
Breaking down compounds must involve a chemical change. Chemical change is a
change that produces matter with a different composition that the original matter. For
example when sugar is heated until it burns a chemical change has occurred. Sugar has
been changed into solid carbon and water vapor.
The water is a compound that can be broken down further into the elements hydrogen and
oxygen. This is accomplished by passing electricity through the water.
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Properties of Compounds
The properties of compounds are generally very different than their component elements.
For example sucrose is a sweet tasting compound, but carbon is a black tasteless solid.
When the elements sodium and chlorine combine chemically to form sodium chloride,
there is a change in the composition and a change in properties. Sodium is a soft gray
metal. Chlorine is a pale yellow green poisonous gas. Sodium Chloride is a white solid.
Distinguishing Substances and Mixtures
If the composition of a material is fixed, the material is a substance. If the composition
of a material may vary, the material is a mixture.
Flow Chart Summarizes the Process for Classifying Matter
(Please complete the chart)
Symbols and Formulas
Each element is represented by a one- or two-letter chemical symbol. The first letter of
the chemical symbol is always capitalized. When a second letter is used, it is lowercase.
If the English name and the Latin name of an element are similar the symbol will appear
to have been derived from the English name. Examples include Ca for Calcium, N for
Nitrogen and S for sulfur. The table below shows examples of elements where the
symbols do not match the English names.
Name
Sodium
Potassium
Antimony
Copper
Symbol
Na
K
Sb
Cu
Latin Name
Natrium
Kalium
Stibium
Cuprum
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SHS Chemistry
Gold
Silver
Iron
Lead
Tin
September 2014
Au
Ag
Fe
Pb
Sn
Mrs. Kaiser
Aurum
Argentum
Ferrum
Plumbum
Stannum
Chemical symbols offer a shorthand way of writing compounds. The formula for water
is H20. The formula for sucrose or table sugar is C12H22O11. Subscripts in chemical
formulas are used to indicate the relative proportions of the elements in the compound.
For example the subscript 2 in H20 indicates that there are always two parts of hydrogen
for each part oxygen in water. Because a compound has fixed composition, the formula
for a compound is always the same.
Chemical Reactions
Words such as burn, rot, rust, decompose, ferment, explode and corrode usually signify a
chemical change.
Remember that during a chemical change, the composition of matter always changes.
For example when iron and sulfur are heated they react to form iron sulfide (FeS).
A chemical change is also called a chemical reaction. A substance that is present at the
start of the reaction is a reactant.
A substance produced in the reaction is a product. In the reaction of iron and sulfur, iron
and sulfur are reactants and iron sulfide is the product.
Recognizing Chemical Changes
Possible clues to chemical change include a transfer of energy, a change in color, the
production of a gas, or the formation of a precipitate. But the only way to be sure that a
chemical change has taken place is test the composition of a sample before and after the
change.
Conservation of Mass
When wood burns, substances in the wood combine with oxygen from the air. As the
wood burns, a sizable amount of matter is reduced to a small pile of ashes. The reaction
seems to involve a reduction in the amount of matter. But appearances can be deceiving.
During any chemical reaction, the mass of the products is always equal to the mass of the
reactants. Two products of burning wood, carbon dioxide and water vapor are released
into the air. When the masses of these gases are considered, the amount of matter is
unchanged.
Mass also holds constant during any physical change. The law of conservation of mass
states that in any physical change or chemical reaction, mass is conserved. Mass is
neither created nor destroyed.
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September 2014
Mrs. Kaiser
Chapter 3
Section 3.1
Accuracy – is a measure of how close a measurement comes to the actual or true value of
whatever is measured
Precision is a measure of how close a series of measurements are to one another.
To evaluate the accuracy of a measurement, the measured value must be compared to the
correct value. To evaluate the precision of a measurement, you must compare the values
of two or more repeated measurements
Significant Figures in Measurements
Significant figures in a measurement include all of the digits that are known, plus a last
digit that is estimated. Measurements must always be reported to the correct number of
significant figures because calculated answers often depend on the number of significant
figures in the values used in the calculation.
Rules for Determining Whether a Digit in a Measured Value is Significant:
1. All digits 1-9 inclusive are significant.
Example: 129 has 3 significant figures
2. Zeros between significant digits are always significant.
Example: 5007 has 4 significant figures
3. Trailing zeros in a number are significant only if the number contains a decimal
point. Example: 100.0 has 4 significant figures. 100 has 1 significant figure.
4. Zeros in the beginning of a number whose only function is to place the decimal point
are not significant.
Example: 0.0025 has 2 significant figures
5. Zeros following a decimal significant figure are significant.
Example: 0.000470 has 3 significant figures
0.47000 has 5 significant figures
6. There are two situations that the concept of significant figures is not applicable. The
first involves counting. If you count 23 people in your classroom, then there are
exactly 23 people and no need to mention a significant figure. The second situation
involves exactly defined quantities such as those found within a system of
measurement. When, for example, you write 60 min = 1 hr, or 100 cm = 1 m, each of
these numbers is exact and does not need significant figures. As you shall soon see,
exact quantities do not affect the process of rounding an answer to the correct
number of significant figures.
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September 2014
Mrs. Kaiser
Significant Figures in Calculations
For example find the area of a floor that measures 7.7 meters by 5.4 meters. The
calculator gives you an answer of 41.58 square meters. The calculated area is expressed
to four significant figures. However, each of the measurements used is only expressed in
two significant figures. So, the answer must also be reported in two significant figures
(42 meters squared or 42 m2)
In general, a calculated answer cannot be more precise than the least precise
measurement from which it was calculated. The calculated value must be rounded to
make it consistent with the measurements from which it was calculated.
Error = experimental value – accepted value
Percent error = ___error_______ x 100%
Accepted value
Example: Just because a measuring device works doesn’t necessarily mean that it is
accurate. For example, Sometimes my bathroom scale does not read zero when nothing
is on it. This scale is bound to yield error. In order to weigh accurately, I must first
make sure the scale is zeroed (tared).
Rounding
To round a # you must first determine the number of significant figures in the answer.
Once you know, then you round to that number of digits, counting from the left. If the
digit immediately to the right of the last significant digit is less than 5, it is simply
dropped and the value of the last significant digit stays the same. If the digit in question
is 5 or greater, the value of the digit in the last significant place is increased by 1.
For example:
3.2 The International System of Units (SI)
S.I. is a updated version of the metric system.
SI Base Units
Quantity
SI Base Unit
Length
Meter
Mass
kilogram
Temperature
Kelvin
Time
Second
Amount of substance
Mole
Luminous intensity
candela
Electric current
Ampere
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Symbol
M
Kg
K
S
Mol
Cd
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SHS Chemistry
September 2014
Commonly Used Metric Prefixes
Prefix
Meaning
mega (M)
1 million times larger than
the unit it preceded
kilo (k)
1000 times larger than the
unit it precedes
deci (d)
10 times smaller than the
unit it precedes
centi ©
100 times smaller that the
unit it precedes
milli (m)
1000 times smaller than the
unit it precedes
micro (u)
1 million times smaller than
the unit it precedes
nano (n)
100 million times smaller
than the unit it precedes
pico (p)
1 trillion times smaller than
the unit it precedes
Mrs. Kaiser
Factor
10 6
10 3
10-1
10-2
10-3
10-6
10-9
10-12
Units and Quantities
Unit of Length
In SI the base unit of length is the meter (m).
Common metric units of length are the centimeter, meter and kilometer
Metric Units of Length
Unit
Kilometer (km)
Meter (m)
Decimeter (dm)
Centimeter (cm)
Millimeter (mm)
Micrometer (um)
Nanometer (nm)
Relationship
1 km = 103 m
Base unit
10 1 dm = 1m
10 2 cm = 1m
10 3 mm= 1 m
10 6 um = 1 m
10 9 nm = 1 m
Example
Unit of Volume
Common metric units of volume include the liter, milliliter, cubic centimeter, and
microliter.
Metric Units of Volume
Unit
Liter (L)
Milliliter (mL)
Cubic centimeter (cm3)
Microliter (uL)
Relationship
Base unit
10 3 mL = 1 L
1 cm 3 = 1 mL
10 6 uL = 1 L
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Example
SHS Chemistry
September 2014
Mrs. Kaiser
Units of Mass
Common metric units of mass include the kilogram, gram, milligram and microgram.
Metric units of Mass
Unit
Kilogram (kg) (base unit)
Gram (g)
Milligram (mg)
Microgram (ug)
Relationship
1 kg = 10 3 g
1 g = 10 –3 kg
10 3 mg = 1 g
10 6 ug = 1 g
Example
Units of Temperature
Scientists commonly use two equivalent units of temperature, the degree Celsius and the
kelvin.
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Mrs. Kaiser
3.4 Density (ASK: How is density like a heart?)
Density = Mass
Volume
Density is an intensive property that depends only on the composition of a substance, not
on the size of the sample (ask: Which planet would float in water)
Density generally decreases as temperature increases
Define the following vocabulary words on a separate sheet of paper
VOCABULARY:
Chapter 1: Chemistry, alchemy, Antoine-Laurent Lavoisier, Scientific Method,
Observation, Hypothesis, Experiment, Independent variable, Dependent variable, Theory,
Scientific law.
Chapter 2: Mass, volume, substance, malleable, conductivity, malleability, solid, liquid,
gas, physical change, mixture, heterogeneous mixture, homogeneous mixture, phase,
filtration, distillation, element, compound, chemical symbol, chemical reaction, reactant,
product, chemical change, conservation of mass.
Chapter 3: Accuracy, precision, percent error, significant figures, density
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