CHEMISTRY PACKET 1:
SECTIONS I AND II (PG. 351)
Chemistry
2014-2015
IMPORTANT DATES
Safety Contract due Th 8/28
Safety Quiz Th 8/28 (you MUST pass this quiz
and turn in your completed Safety Contract
before you can participate in labs)
Section I/II Quiz F 9/12
Section I/II Test W 9/17
Element Research Project due M 9/29
Labs on F 8/29, W 9/3, M 9/8
SECTION I DEFINING
MATTER
LAB EQUIPMENT AND SAFET Y
Chemists have specific tools and
equipment that they use to study
the world around them. They
also have a set of guidelines for
using tools and chemicals safely.
THE TOOLS CHEMISTS USE
 Commonly-used equipment can be found
on a page in this packet. You will need to
be able to identify these pieces of
equipment for your quiz/test, as well as on
a daily basis.
 The most accurate glassware to use for measuring
liquid is a volumetric pipette (or just a pipette —
these are not the flimsy plastic ones, but glass
ones with clear markings on the side). Other
accurate glassware pieces include the graduated
cylinder and the burette. Erlenmeyer flasks and
beakers are not considered accurate .
Some containers are safe for heating
substances. These include test tubes, beakers,
flasks, crucibles, and evaporating dishes.
One common piece of equipment that is not
shown in your packet is the hot plate.
LABORATORY SAFET Y
Know the location of safety equipment and
how to use it.
 Safety Shower: near calculators
 Eye Wash: near calculators, attached to safety
shower (must wash eyes for 15-20 minutes)
 First Aid Kit: front of class, below clock
 Fire Blanket: next to safety shower (used to smother
fires)
 Fume Hood: back corner of classroom (used to
contain fumes or smoke)
 Fire Extinguisher: below fire blanket
Laboratory Safety:
Dress appropriately (roll up sleeves, tie hair
back, wear closed-toe shoes); read
instructions carefully; double-check that
you are using the correct chemicals; do not
put chemicals back into their original
bottles; wear goggles; clean up your station
and return equipment to its proper place
before you leave the lab; if you have any
questions in the lab, or if an accident
occurs, ask/tell your teacher .
Personal safety
equipment:
goggles, gloves, apron
Classroom safety equipment: fire
blanket, fire extinguisher, safety
shower, eye wash station, fume hood
INTRODUCTION TO CHEMISTRY
The Roots of Chemistry
 More than a thousand years ago, people known as
alchemists tried to transform substances into other
substances (ex. turning ordinary metals into gold).
They never succeeded, but as alchemists conducted
experiments and looked over their successes and
failures, they gradually created the early study of
Chemistry. (Today we know that it actually is
possible to convert one element to another, but it’s a
very different process and sadly, it does not allow one
to turn base metals into gold.)
When the alchemists succeeded in making new
substances, they faced the challenge of
determining whether each substance was gold.
In other words, the alchemists needed to figure
out if the new substance had the properties of
gold.
A property is a characteristic or quality of
a substance. You are going to try a similar
experiment tomorrow by turning a penny
from copper to silver to gold. You will
need to write a hypothesis to explain what
happens.
A hypothesis is a proposed explanation for
an observation or scientific problem,
which can be tested by further
investigation (it is not an educated guess).
THE STUDY OF MATTER AND CHANGE
Changes are constantly happening
around us. These can be exciting
(exploding fireworks) or mundane
(baking cookies, which is still pretty
nice). Chemistry is the study of what
substances are made of, how they
behave, and how they can be
transformed. It is the study of matter
and how matter changes.
DEFINING MATTER
Matter is the word chemists use to refer to all
the materials and objects in the world.
Although many examples of matter are
obvious (your desk, your phone, you), your
senses alone are not always enough to tell you
whether something is matter (you can’t see
viruses, but you can still get sick from them,
for example).
The amount of substance, or material, in an
object is called its mass. Mass is a
property of matter that can be measured.
(It is also the same no matter where you
are; weight, however, is not.) The amount
of space something takes up is called its
volume and is also a property of matter
that can be measured. So, matter is
anything that has mass and volume.
IS IT MATTER?
Solids, liquids, and gases are all
composed of matter.
Some things may seem like matter,
but are not. Matter must have mass
and it must take up space.
Examples of non-matter include heat
and sound. Ideas also are not
matter.
MEASURING MATTER
 Chemists measure mass in grams (g) and kilograms
(kg). There are 1000 g in 1 kg.
 Electronic balances and triple-beam balances can be
used to measure mass. With both of these balances,
mass must be measured and recorded as exactly as
possible; it may seem to make sense to round, but
rounding can affect your lab work (and your lab
grade—don’t do it). If you use an electronic balance,
record all digits shown. For triple beam balances,
estimate one more decimal place than you can read.
Chemists measure the volume of liquids and
gases in milliliters (mL) and liters (L). There
are 1000 ml in 1 L. You can measure the
volume of a sample of a liquid by pouring it
into a graduated cylinder and reading the
number of mL on the side. Make sure to read
the liquid level at the bottom of the meniscus
(the curvature of the top of the liquid).
Fun fact—
mercury’s
meniscus
bends the
opposite
way.
You can measure the volume of a
regularly shaped solid object by
measuring its dimensions in centimeters
(length, width, height) and using a
mathematical formula. This will give you
volume in cubic centimeters (cm 3). 1 cm 3
= 1 mL.
In certain cases, you can
use water displacement
(shown on the right with
the dinosaur) to determine
the volume of a (small,
insoluble) solid.
Read the initial water
volume; add the object;
read the new volume; and
subtract.
5.60 mL
What was the volume of
the dinosaur? ________ mL
= ________ cm 3
- 4.80 mL = 0.80 mL
= 0.80 cm3
MASS AND VOLUME
 It is possible for two substances to
have the same volume but different
masses, or the same mass but different
volumes. For example, 1.0 cm 3 of gold
has a mass of 19.3 g, but 1.0 cm 3 of
copper has a mass of 9.0 g. This
means that if you had the same mass
of each, the copper would take up more
space (have more volume) than the
gold. This is due to a difference in
density.
DENSIT Y
Which is heavier, copper or gold? If you
have equal volumes of each, the gold will
always be heavier. This is due to density,
which is the mass of a substance per unit
of volume.
The formula for calculating
density is shown on the right.
Density is calculated by
dividing mass by volume,
so its units are g/mL or g/ cm 3 .
PACKET 1 EXAMPLE 1: DENSIT Y
A piece of metal has a volume of 30.0 cm 3
and a mass of 252 g. What is its density?
Density = mass / volume
= 252 g / 30.0 cm3
= 8.40 g/cm3
IDENTIFYING MATTER USING DENSIT Y
The density of a substance does not change
with its size or shape. In other words, density
is an intensive property (a property that does
not change if the quantity of the substance
changes). Intensive properties can be used to
identify substances. (On the other hand,
extensive properties
DO change depending on the
amount of matter—examples
include mass and volume.)
Because density is an
intensive property, it can
be used to help identify
the type of matter that
an object or sample is
made of. First,
calculate the density of
an object, then compare
it with known density
values in a reference
table like the one on the
right.
Metal
Density
Copper
9.0 g/ cm3
Zinc
7.1 g/ cm3
Gold
19.3 g/ cm3
Lead
11.4 g/ cm3
Aluminum
2.7 g/ cm3
Brass
8.4 g/ cm3
PACKET 1 EXAMPLE 2: THE FAKE BAR OF
GOLD
If someone tried to trick
you by coating a block of
lead with a thin layer of
gold, how could you
prove the bar is fake?
Use its mass and volume to
determine its density. If the bar is
actually lead coated with gold, its
density will be higher than 8.4 g/cm3
(the density of lead is 11.4 g/cm3).
Metal
Density
Copper
9.0 g/ cm3
Zinc
7.1 g/ cm3
Gold
19.3 g/ cm3
Lead
11.4 g/ cm3
Aluminum
2.7 g/ cm3
Brass
8.4 g/ cm3
PACKET 1 EXAMPLE 3: USING DENSIT Y
TO IDENTIFY A METAL
Look back at Example 1.
What type of metal is
this, and how do you
know?
The metal is brass; its
density is 8.4 g/cm3.
Metal
Density
Copper
9.0 g/ cm3
Zinc
7.1 g/ cm3
Gold
19.3 g/ cm3
Lead
11.4 g/ cm3
Aluminum
2.7 g/ cm3
Brass
8.4 g/ cm3
SECTION II BASIC
BUILDING MATERIALS
CHEMICAL NAMES AND SYMBOLS
 Some chemical names are used in daily language
(ex. aluminum, iron, ammonia). Other names are
used mainly by chemists, such as sodium chloride for
salt and sodium bicarbonate for baking soda .
 Elements are the building materials of all matter.
There are about 118 known elements; each one has a
name and a symbol. The chemical symbol may be an
abbreviation for the element’s name, but it is
sometimes taken from a word in another language
instead.
Name Mercury Copper Carbon Phosphorous Gold Iron
Symbol Hg
Cu
C
P
Au
Fe
Elements combine in specific
ratios to form compounds. A
compound is represented by a
chemical formula. For example,
sodium chloride is NaCl and
consists of a 1:1 ratio of sodium
and chlorine. The chemical
formula for carbon dioxide is CO 2,
which means it consists of a 1:2
ratio of carbon to oxygen (there
are two oxygen atoms for every
carbon atom).
Compounds can be very different in behavior
and appearance from the elements they are
composed of. For example, sodium is a shiny,
soft, reactive metal and chlorine is a deadly
gas, but sodium chloride is a white crystal
that is relatively nontoxic.
PHYSICAL FORM
 Elements can exist as solids, liquids, or gases; these are
represented with the symbols (s), (l), and (g) after the
chemical formula. These are called the phases of matter. For
example, water vapor is written H 2 O(g), liquid water is written
H 2 O(l), and ice is written H 2 O(s).
 There is another symbol for physical form, the symbol ( aq) for
aqueous. A substance is aqueous if it is dissolved in water
(therefore, it has to be soluble).
Most substances are mixtures of compounds. In
a mixture, the different substances do not have
to be present in a specific ratio. For example,
you can make chocolate chip cookies with ½
cup of chocolate chips per batch, or 2 cups of
chocolate chips per batch. They’re still
chocolate chip cookies.
THE COPPER CYCLE
 Copper is an element with the symbol Cu. As a solid powder,
it has a distinctive orange -brown appearance. You are going
to transform copper powder through a series of chemical
reactions. If all works well, copper should reappear by the
end of the experiment.
 Evidence of a Chemical Change
 A chemical change or chemical reaction is a transformation that
alters the composition of one or more substances such that one or
more new substances with new properties are produced. You can
usually tell when a chemical reaction occurs because there is
evidence of new substances forming.
 Evidence of a chemical change includes a color change, evolution
(production) of a gas, production of light, and a change in smell.
CONSERVATION OF MATTER
 The copper cycle
experiment brought you
back full circle. No
matter what was done to
the copper, the copper
was always present in
some form. In other
words, it was not created
or destroyed during the
chemical
transformations, but its
form was changed during
each step.
Over many centuries,
scientists have gathered
evidence that matter can
never be destroyed or
created through a chemical
change—enough evidence
that this is considered a
scientific law. The law of
conservation of mass states
that mass cannot be gained
or lost in a chemical
reaction—that matter
cannot be created or
destroyed.
PROPERTIES OF THE ELEMENTS
 As alchemists and chemists explored the
world around them, they discovered a large
number of elements. It became clear that
these elements needed to be organized. In
the late 1960’s, a Russian chemist and
teacher named Dmitri Mendeleyev created
his own organizational scheme by putting
elements in groups based on similarities in
their properties. Some of these properties
are listed below.
 Reactivity
 Ratios in compounds
 Atomic mass
Reactivity is a property
that describes how easily
an element will combine
with other substances to
form new compounds. An
element that is highly
reactive combines rapidly
with other substances.
For example, when
metallic sodium comes
into contact with water, it
reacts vigorously.
 Mendeleyev also paid attention to which
elements combine with which, and he noted the
ratios in which their atoms combine. For
example, magnesium combines with chlorine in a
1:2 ratio, while sodium combines with chlorine in
a 1:1 ratio. This means that magnesium and
sodium must have similar reactivity (since both
can combine with chlorine), but not exactly the
same.
 Mendeleyev used another property --atomic mass-to sort the elements. Atomic mass is the mass of
an atom, and it is measured in atomic mass
units, or amu. The elements can be placed in
order of their atomic masses. However, this alone
does not tell you which elements are similar by
properties.
 Mendeleyev put the elements with similar reactivity
and chemical formulas of compounds into columns. He
also sorted them by atomic mass, from smallest to
largest. This way, the elements in each column have
similar physical properties and reactivity, and they tend
to form compounds with other elements in the same
ratios. This table became the foundation of the
modern periodic table of elements.
THE PERIODIC TABLE
Scientists have detected around 114 elements
on the planet (there are about 118 total).
Each element is unique, but groups of
elements have similar properties.
Each element has a square on the periodic
table. Within each square is information about
that element including its name and symbol.
The whole number (usually at the top of each
square) is called the atomic number. The
decimal number in each square on the periodic
table is the average atomic mass in amu.
 Most modern periodic tables have 18 vertical columns
and 7 horizontal rows. The vertical columns are also
called groups or families. The horizontal rows of the
table are called periods because patterns repeat
periodically (over and over again) in each row.
 Chemists also have names for the sections of the
periodic table.
 The main group elements include groups 1A (alkali metals), 2A
(alkaline earth metals), and 3A -8A (group 7A are the halogens, and
group 8A are the noble gases).
 The transition metals are in the middle of the periodic table.
 The inner transition metals are below the periodic table. This
section consists of the lanthanides and actinides.
 Solids, liquids, and gases: most of the elements are
solid at room temperature. Several are gaseous at
room temperature; only three (gallium, bromine, and
mercury) are liquid at room temperature.
Metals, metalloids, and nonmetals
 The majority of the elements are metals. On most
periodic tables there is a stair-step line that divides
the table. Metals are found to the left and nonmetals
are found to the right. The elements found along the
stair-step are called metalloids (similar properties to
both metals and nonmetals).
Reactivity: elements in the lower left and
upper right of the periodic table (excluding
noble gases) are the most reactive. On the
other hand, elements in the middle of the
periodic table, such as copper, silver, and
gold, are not very reactive.
FUN FACT
It is illegal to purchase francium in the United States
due to its violently explosive reaction with water.
FUN FACT
Gold is very nonreactive, but it can dissolve in aqua regia, a
concentrated 1:3 mixture of nitric acid and hydrochloric acid. This
reaction was used to keep two Nobel Prize medals out of Nazi
hands in the 1940’s (the metals were dissolved; the dissolved gold
was stored in common glassware; and after the war, the Nobel
Foundation recast the medals using the dissolved gold).