chem1101a lect 1
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8/3/2019 Chem1101A Lect 1
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INTRODUCTORY CHEMISTRY
CHEM 1101A
Lecturer: Dr. Duanne Biggs
Email: [email protected]
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Outline
States of matter
Kinetic particle Theory
Element, compounds and mixtures
Solutions, suspensions and colliods
Methods of separation
Gas Laws: Boyle’s Law, Charles Law,Gay-Lussac Law
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STATES OF MATTER
• The Four States of Matter
• Four States
• Solid
• Liquid
• Gas• Plasma (General Knowledge)
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STATES OF MATTER
Based upon particle arrangement
Based upon energy of particles
Based upon distance between particles
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Kinetic Particle Theory
• KPT is just the view that everything is made of
tiny particles that are in motion, hence theterm “kinetic”. This topic is concerned with
exhibited by these particles.
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Characteristics of the 3 states
• Solid: Particles are closely packed in an orderly
arrangement, and vibrate in fixed positions.
• L qu : Partic es are oose y arrange ut sticlose together, and move randomly.
• Gas: Particles are far apart, with no
arrangement, and move randomly.
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States of Matter
SolidsParticles of solids are tightly
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,
position.
Solids have a definite shape and adefinite volume.
Solids have an infinite number of free surfaces.
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States of Matter
LiquidsParticles of liquids are tightly
packed, but are far enough apart
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to slide over one another.
Liquids have an indefinite shape
and a definite volume.
Liquids have one free surface.
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States of Matter
GasesParticles of gases are very far apart and move
freely.
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Gases have an indefinite shape and an
indefinite volume.
Gases have no free surfaces.
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States of Matter
Plasma
A plasma is an ionized gas.
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A plasma is a very good conductor of electricity and is affected by magnetic fields.
Plasma, like gases have an indefinite shapeand an indefinite volume.
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States of Matter
Sublimation is the conversion of a solid directly to
a gas without passing through the liquid state;the reverse of that process is called deposition.
Water is a substance that is familiar to us in allthree physical states. The molecules are closetogether in the solid and the liquid but far apart
in the gas. The molecules in the solid arerelatively fixed in position, but those in the liquidand gas can flow around each other.
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States of Matter
The changes shown in blue are endothermic (absorb
heat); those shown in red are exothermic (release heat).12
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STATES OF MATTER
SOLID LIQUID GAS PLASMA
Tightly packed, in a
regular pattern
Vibrate, but do not
move from place to
place
Close together with
no regular
arrangement.
Vibrate, move
about, and slide
past each other
Well separated with
no regular
arrangement.
Vibrate and move
freely at high
speeds
Has no definite
volume or shape
and is composed of
electrical charged
particles
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Energy
• Changes from one state to another involve the
gain or loss of energy. Energy is absorbed togive particles more energy, while energy is lost
.
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Compounds and Mixtures
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Elements and Chemical
Compounds
Elements are pure substances that contain
only one kind of atom.
Chemical compound is a pure substance that
different elements combine and create a new
material with properties completely unlike
those of its constituent elements.
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Mixtures
• Mixtures are simply blends of two or more
substances added together in some randomproportion without chemically changing the
• Heterogeneous
• Homogeneous
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Heterogeneous mixtures
Heterogeneous mixtures are those in which the
mixing is not uniform and which thereforehave regions of different composition.
• Components are distinguishable
Examples: fruit salad, vegetable soup, etc.
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Homogeneous mixtures
• Homogeneous mixtures are those in which
the mixing is uniform and which thereforehave a constant composition throughout.
• Components are indistinguishable
• May or may not scatter light
Examples: milk, yogurt, etc.
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Matter
Arrows indicate the general means by which matter can beseparated
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Separation
A mixture of iron and sulfur is a heterogeneous mixture.
Like any mixture, it can be separated by physical means,
such as removing the iron with a magnet. 21
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Solution
A solution is a homogeneous mixture of two or
more components. The dissolving agent is thesolvent. The substance which is dissolved is the
.
Example: Sugar and water
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Suspensions
• The particles in suspensions are larger than
those found in solutions. Components of asuspension can be evenly distributed by a
,
contents, but the components will settle out.
• Example: Oil and Water
»Sand in water
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Colloids
• Particles intermediate in size between those
found in solutions and suspensions can bemixed such that they remain evenly
.
• Eg: Smoke – air is called the continuous phase
- the particles are called the
disperse phase• Example: starch in water
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GAS LAWS
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GAS LAWS• Unlike solids and liquids, different gases show
remarkably similar physical behavior
regardless of their chemical makeup. Gasesare considered fluids.
“
flow.”
• Gases Have Low Density
• Gases Are Highly Compressible• Gases Completely Fill a Container
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GAS LAWS
• Physical properties of any gas can be defined
by four variables: pressure (P)
temperature (T),
vo ume V ,number of moles (n).
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GAS LAWS
Boyle’s Law:
for a fixed amount of gas (n) at a constant
temperature (T), the volume of the gas
and the volume of the gas decreases as the
pressure of the gas increases
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GAS LAWS
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GAS LAW
• Charles’ Law: The Relationship Between
Volume and Temperature
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GAS LAWS
• Charles’ Law:
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GAS LAWS• Gay-Lussac’s law: the law that states that the
pressure of a gas at a constant volume is directlyproportional to the absolute temperature.
Pressure of a as is ro ortional to its absolute
temperature, the following equation is true for asample of constant volume.
P = kT
This equation can be rearranged to the followingform.
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GAS LAWS
Gay-Lussac’s Law
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