Chemistry Chapter 1
Introduction to
Chemistry
How to succeed in chemistry
• Positive attitude:
believe you can!
• Listen in
class/take good
notes
• Memorize what I
ask you to/figure
out the rest
• Read the chapters
• Self-check
exercises/odds
(practice)
• Complete
homework ahead
of time (so can
ask questions!)
• Keep an organized
notebooks
• Study!
What is CHEMISTRY?
Chemistry is…
… The study of matter
and the changes it
undergoes
C2H5OH + 3 O2  2 CO2 + 3 H2O + Energy
Reactants

Products
Matter
Anything that has mass and occupies space
Mass
A measure of the amount of matter
Weight
The measure of the amount of matter in and
the gravitational force exerted on the
object. (product of mass and the local
acceleration of gravity)
In general terms: “the heaviness” of an
object
Model
A visual, verbal, or mathematical explanation
of experimental data.
Branches of Chemistry
Table 1.1, p. 11
Chemistry is the “Central Science”
What are chemists?
Who are chemists?
You must be more than a talking
head…..
Steps for Problem Solving/The
“Scientific Method”:
1. Make observations-something that is
witnessed and can be recorded
2. State the problem
3. Form hypothesis-testable statements or
predictions to propose possible solutions
4. Decide what is reasonable and perform
experiments. (must be able to THINK
CRITICALLY and creatively)
5. Analyze the data
6. Form conclusions (done/replicate, or
start again?)
Figure 1.1:
The various parts
of the scientific
method.
Type of Observation or Data
• Quantitative: Numerical information describing
a quantity. It usually includes a number and a
unit (454.6 g, 2.2 lb., 25 students)
• Qualitative: Describes a quality of the data
such as color, odor, shape, or some other
physical characteristic (granular, white)
Theory or a Law?
• Theory: (model) tested set of hypothesis that
gives an overall EXPLANATION of some part of
nature. (tells WHY it happens)
– Quantum Theory
• Law: A summary of accepted facts of nature.
(tells WHAT happened again and again and
again)
– Law of chemical equilibrium
– Law of conservation of energy
– Law of conservation of mass
Problem/Observation:
This plant is dying…
1. Propose possible solutions.
(or hypothesis)
1. Decide how to test them.
2. Test them.
3. Evaluate results.
4. Possibly draw conclusion.
Controlled Experiments
1. Independent Variable-the variable that
will be manipulated or changed
2. Dependent Variable-the variable whose
value depends on the independent
variable
3. Constants-what is kept the same
throughout the experiment to keep
“samey samey”
4. Control-the standard that is used for
comparison
Types of Research
1. Pure Research-to gain knowledge for
the sake of knowledge itself
2. Applied Research-research undertaken
to solve a specific problem
Ozone Case Study
1. O2 + UVC  O + 0
2. O + O2  O3
3. O3 + UVB or UVC  O2 + O
First three steps: normal containment of
UV radiation
1. O3 + Cl  ClO + O2
2. ClO + O  Cl + O2
A single chlorine molecule can break down
100,000 ozone molecules
Chemistry Chapter 3
Matter—Properties
and Changes
Atom
The smallest unit of an element that maintains
the properties of that element
Element
A pure substance that cannot be broken down
into simpler substances by physical or chemical
means.
Top Ten
Compound
A substance that is made from the atoms of two or
more elements that are chemically bonded.
Sucrose – C12H22O11
Sucrose is also known
as table sugar, and is
used to make Gummy
Bears!
Atom Combinations
Physical Change
A change in a substance that does not involve a
change in the identity of the substance.
Example:
Phase Changes
Figure 2.7:
The three states
of matter: solid.
Solid: a form of
matter that has its
own definite shape
and volume
Figure 2.7:
The three states
of matter: liquid.
Liquid: a form of
matter that flows,
has constant
volume and takes
the shape of its
container
Figure 2.7:
The three states
of matter: gas.
Gas: a state of
matter that takes
the shape and
volume of its
container
Vapor: the
gaseous state of a
substance
Copper Phases - Solid
Copper Phases - Liquid
Copper Phases – Vapor (gas)
Phase
Differences
Solid – definite volume and shape; particles packed
in fixed positions.
Liquid – definite volume but indefinite shape;
particles close together but not in fixed positions
Gas – neither definite volume nor definite shape;
particles are at great distances from one another
Plasma – high temperature, ionized phase of matter
as found on the sun.
Physical Changes/Properties
• Physical change: A type of change that alters
the physical properties of a substance but does
not change its composition
• Physical property: A characteristic that can be
observed or measured without changing the
sample’s composition (density, color, odor,
hardness, melting point, boiling point)
– Extensive: dependent of the amount of
substance present (mass, length, volume)
– Intensive: independent of the amount of
substance present (density)
Figure 2.15: No chemical change
occurs when salt water is distilled.
Chemical Change
A change in which one or more substances are
converted into different substances.
Heat and light are
often evidence of
a chemical change.
Chemical Property
The ability of a
substance to
combine with or
change into one or
more other
substances
Figure 2.8:
Electrolysis, the
decomposition of
water by an electric
current, is a chemical
process.
Law of Conservation of Mass
massreactants
=
massproducts
States that: mass is neither created nor
destroyed during a chemical reaction
Classification of Matter
Separation of a Mixture
The constituents of the mixture retain their
identity and may be separated by physical
means.
Figure 2.16:
Filtration separates a
liquid from a solid.
Figure 2.17: Separation of a sandsaltwater mixture.
Separation of a Mixture
Distillation
Separation of a Mixture
The components of dyes
such as ink may be
separated by paper
chromatography.
Figure 2.10:
Twenty-four-karat gold is an element.
Eighteen-karat gold is an alloy.
Fourteen-karat gold is an alloy.
Figure 2.9: The composition of air.
Chart
examining
each
substance
of air.
Law of Definite Proportions
States that: A compound is always
composed of the same elements in the
same proportion by mass no matter how
large or small the sample
-the mass of the compound is equal to the
sum of the masses in the elements that
make it up
-can be expressed as % mass
% mass = mass of element
x 100
mass of compound
Law of Multiple Proportions
States that: compounds can be composed
of the same elements in different
ratios (H2O, H2O2) or (CO and CO2)
-
-end Ch. 3
Figure 2.5:
The three forms
of the element carbon:
Diamond.
Figure 2.5:
The three forms of
the element
carbon: Graphite.
Figure 2.5:
The three forms of the
element carbon:
Buckminsterfullerene.
Copyright © by Houghton Mifflin
Company
Figure 2.11:
Representation of
H2O molecules.