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SURVEY OF CHEMISTRY I
CHEM 1151
CHAPTER 1
DR. AUGUSTINE OFORI AGYEMAN
Assistant professor of chemistry
Department of natural sciences
Clayton state university
CHAPTER 1
MATTER
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
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
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
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
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
drinking water, juice
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)
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.
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
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
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
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
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
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
melting point, boiling point, density
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
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
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 Earth’s crust
(oxygen, silicon, aluminum, iron, and calcium)
- Only 3 elements account for over 90% of the human body mass
(oxygen, carbon, hydrogen)
CHEMICAL COMPOSITION
Elements
The symbol for each element consists of one or two letters derived
from the element’s name, with the first letter capitalized
Carbon
Aluminum
Barium
Beryllium
Copper
Flourine
Iron
Gallium
Some elements and their symbols
C
Germanium Ge
Nitrogen
Al
Hydrogen
H
Sodium
Ba
Helium
He
Nickel
Be
Mercury
Hg
Oxygen
Cu
Iodine
I
Phosphorus
F
Lithium
Li
Lead
Fe
Magnesium Mg
Platinum
Ga
Manganese Mn
Sulfur
N
Na
Ni
O
P
Pb
Pt
S
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)
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)
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)
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
CLASSES OF MATTER
MATTER
PURE
SUBSTANCE
ELEMENT
COMPOUND
MIXTURE
HOMOGENEOUS
MIXTURE
HETEROGENEOUS
MIXTURE