SURVEY OF CHEMISTRY I CHEM 1151 CHAPTER 1

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SURVEY OF CHEMISTRY I CHEM 1151CHAPTER 1
DR. AUGUSTINE OFORI AGYEMAN Assistant professor
of chemistry Department of natural
sciences Clayton state university
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CHAPTER 1MATTER
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CHEMISTRY AND MATTER
Chemistry - Is the study of matter and energy
and the interactions between them - Involves
studying the properties and behavior of
matter Matter - Anything that has mass and
occupies space Examples - Living and
nonliving things - Things that can be seen
animals, plants, soil, water, clothes, books -
Things that cannot be seen air, bacteria
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CHEMISTRY AND MATTER
Energy - The ability to do work - Forms of
energy (sound, heat, light) are NOT considered
to be matter Mass - Amount of matter in an
object Volume - The amount of space that the
matter takes up
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CHEMISTRY AND MATTER
Difference between Mass and Weight Mass - is a
measure of total quantity of matter in an
object - constant and independent of location -
instrument the mass balance Weight - is a
measure of the force exerted on an object by
gravitational force - weight mass x
gravitational force - changes with location
(e.g. gravitational attraction on the moon is
1/6th that on the earth) - instrument spring
scale
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PHYSICAL STATES OF MATTER
Three physical states of matter solid, liquid,
and gas Solid - Has a definite shape and a
definite volume Examples ice, book, table, TV
set
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PHYSICAL STATES OF MATTER
Three physical states of matter solid, liquid,
and gas Liquid - Has an indefinite shape and a
definite volume - Always takes the shape of its
container (the portion it occupies) Examples drin
king water, juice
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PHYSICAL STATES OF MATTER
Three physical states of matter solid, liquid,
and gas Gas - Has an indefinite shape and an
indefinite volume - Always completely fills its
container, taking the shape and volume of the
container Examples air, water vapor (steam)
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PHYSICAL STATES OF MATTER
State of matter depends on - Temperature -
Surrounding pressure - Strength of forces holding
the structural particles together - Water can
be found in all three physical states solid ice,
liquid water, and gaseous steam.
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PROPERTIES OF MATTER
Two categories physical and chemical
properties Physical Property - Does not change
the identity or composition of a substance - Does
not involve changing a substance into
another Examples shape, color, odor, density,
taste, feel, mass, volume phase, melting point,
boiling point, hardness
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PROPERTIES OF MATTER
Two categories physical and chemical
properties Chemical Property - Involves
changing a substance into another
substance (chemical reactions) - Describes the
reactivity of a material Examples heat of
combustion, flammability, enthalpy of formation,
explosiveness, toxicity, ionization potential,
electronegativity
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PROPERTIES OF MATTER
Two categories physical and chemical
properties Chemical Property - Failure to
undergo a chemical change is also considered a
chemical property Examples - inability of glass
to burn - gold not reacting with water
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PROPERTIES OF MATTER
Two categories of changes in matter physical
and chemical changes Physical Change - When a
substance changes its physical appearance but
not its chemical composition Examples - change
of state (from liquid to gas, from liquid to
solid, etc.) - when liquid water evaporates to
steam or freezes to ice
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PROPERTIES OF MATTER
Two categories of changes in matter physical
and chemical changes Chemical Change - When a
substance undergoes a change in chemical
composition - Undergoes a chemical reaction -
Converts into one or more new substances
Examples - rusting of iron exposed to moist air
- combustion of methane - burning of hydrogen
in air
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PROPERTIES OF MATTER
Properties can also be divided into extensive and
intensive Extensive Property - Depends on the
amount of sample under investigation
Examples mass, volume Intensive Property -
Does not depend on the quantity of sample -
Determines the identity of the sample Examples me
lting point, boiling point, density
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CHEMICAL COMPOSITION
Substance A material that is chemically the same
throughout Pure Substance - Matter that has
distinct properties and definite composition -
Cannot be separated into other kinds of matter by
any physical means Examples pure water, pure
salt
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CHEMICAL COMPOSITION
Elements - Pure substances that cannot be
reduced to simpler substances by normal chemical
means - Fundamental building blocks of all
matter Examples silver, carbon, sodium, oxygen,
hydrogen - Note that O2, N2, S8, are elements
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CHEMICAL COMPOSITION
Elements - 117 elements are known at present -
92 are naturally occurring and 25 are synthesized
in the laboratory - Only 5 elements account for
over 90 of Earths crust (oxygen, silicon,
aluminum, iron, and calcium) - Only 3 elements
account for over 90 of the human body
mass (oxygen, carbon, hydrogen)
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CHEMICAL COMPOSITION
Elements The symbol for each element consists of
one or two letters derived from the elements
name, with the first letter capitalized Some
elements and their symbols
Carbon C Aluminum Al Barium Ba Beryllium
Be Copper Cu Flourine F Iron Fe Gallium
Ga
Germanium Ge Hydrogen H Helium He Mercury
Hg Iodine I Lithium Li Magnesium
Mg Manganese Mn
Nitrogen N Sodium Na Nickel Ni Oxygen
O Phosphorus P Lead Pb Platinum Pt Sulfur S
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CHEMICAL COMPOSITION

• Compounds
• - Pure substances that can be broken into two or
• more simpler pure substances by chemical means
• - Combination of two or more elements
• Examples
• Water (H2O), carbon dioxide (CO2), sodium
  chloride (NaCl)

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CHEMICAL COMPOSITION
Mixture - A combination of two or more pure
substances Examples grains of rice and
wheat cereal and sugar salt and sand -
Components of a mixture can be separated by
physical means (filtration, distillation, the
use of magnet for metals)
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CLASSIFICATION OF MIXTURES
Homogeneous Mixture (Solution) - Is uniform
throughout - Contains only one visibly distinct
phase Examples - sugar or salt dissolved in
water - glass - alloys (copper tin ? Bronze)
(iron, carbon, chromium, and other substances ?
stainless steel) - air (homogeneous mixture of
nitrogen, oxygen, and other substances)
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CLASSIFICATION OF MIXTURES
Heterogeneous Mixture - Does not have the same
composition - Contains visibly different
phases Examples rocks, wood, soils
- Physical combination of substances produces a
mixture - Chemical combination of substances
produces a compound
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CLASSES OF MATTER
MATTER
PURE SUBSTANCE
MIXTURE
HOMOGENEOUS MIXTURE
HETEROGENEOUS MIXTURE
ELEMENT
COMPOUND
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ATOMS AND MOLECULES
Atom - The smallest component of an element
having the chemical properties of the
element Molecule - Made up of two or more
atoms Diatomic Molecule contains two
atoms Triatomic Molecule contains three
atoms ETC.
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ATOMS AND MOLECULES
Homoatomic Molecule - All atoms present are of
the same kind (elements) Heteroatomic Molecule -
Two or more kinds of atoms are present
(compounds) - The molecule is the limit of
physical subdivision (the smallest particle of a
compound) - The atom is the limit of chemical
subdivision
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CHEMICAL FORMULA
- Tells which elements and how many of those
elements make up a compound Example The chemical
formula of sulfuric acid is H2SO4 Conveys the
information that a sulfuric acid molecule
contains - 3 different elements hydrogen (H),
sulfur (S), oxygen (O) - 7 atoms 2 hydrogen
atoms, 1 sulfur atom, 4 oxygen atoms - When a
particular atom is 1 (as in S above) the
subscript is not written
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CHEMICAL FORMULA
Note the difference between CoCl2 and
COCl2 CoCl2 - 2 different elements cobalt (Co)
and chlorine (Cl) - 3 atoms 1 Co atom and 2 Cl
atoms COCl2 - 3 different elements carbon (C),
oxygen (O), and chlorine (Cl) - 4 atoms 1 Co
atom, 1 O atom, and 2 Cl atoms Ca(NO3)2 1 Ca
atom and 2 NO3- atoms N atoms 1 x 2 2 O
atoms 3 x 2 6