Download Matter and Energy Chemistry: Matter: Physics Energy Types of

Matter and Energy
Chemistry:
The study of matter and its changes
Matter:
Anything that has mass and volume
Physics
The study of energy and forces
Energy
The ability to change or move matter.
measured in Joules (J)
Kinetic Energy
(energy due to motion)
All matter has some inherent kinetic energy
Types of Energy:
Kinetic Energy (Movement Energy)
• Thermal Energy
(Heat)
• Radiant Energy
(Light)
Potential Energy (Stored Energy)
• Gravitational Potential Energy
(Relative Position)
• Chemical Potential Energy
(Energy stored in bonds)
Temperature
a measure of the
average
kinetic
energy
of a sample of matter.
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Kinetic Molecular Theory
1.
“Moving Particle Theory”
Matter is made of tiny particles
called atoms, which combine to
form molecules.
3 Main Ideas:
2. Atoms and molecules are in
3. Atoms and molecules move faster
constant random motion
(they are always moving)
as temperature rises.
High Temperature
(faster)
Low Temperature
(slower)
Pressure:
• “Force per
unit area”
• Caused by
collisions of
atoms and
molecules
All chemical reactions can be written as:
chemical equations:
for example:
Methanol + Oxygen 
Carbon Dioxide + Water
REACTANTS
PRODUCTS
or:
CH3OH
+
REACTANTS
O2

CO2 +
HCl / Mg
H2O
PRODUCTS
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Law of Conservation of Mass
Law of Conservation of Energy
“Energy cannot be created or destroyed.”
Matter cannot be created or destroyed
true, but…
…energy can
be transferred
between a system and its surroundings
System:
Surroundings:
• The part of the
universe you are
focusing on.
• In chemistry, this is
usually defined as
the products and
reactants.
Remember:
• Everything else in
the universe.
• In chemistry, this
usually includes lab
equipment such as
thermometers,
glassware, probes,
containers, and the
air in the room.
All chemical reactions involve…
ENERGY TRANSFER
= a release or an absorbtion
of energy
between the system and the surroundings.
Reactants  Products
Energy and Chemical Bonds
• Energy is stored in chemical bonds
• Energy is needed to break bonds.
• Energy is absorbed when bonds are broken.
• Energy is released when bonds form.
C6H12O6 + O2  CO2 + 6H2O + Energy(HEAT)
Energy absorbed
to break these
bonds
<
Energy released
to form these
bonds
Energy and Chemical Reactions:
The energy that is transferred
between system and surroundings
during a chemical reaction
can take many forms:
heat,
light,
sound,
electricity,
movement, …etc.
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Heat
Temperature
• Heat is thermal energy
• Heat is measured
in joules (J)
• Heat flows from hot
objects to cold objects
• Heat flow is evidenced by
changes in temperature
• When heat is absorbed or
released by an object, its
temperature changes as a
result.
• a measure of the
average kinetic energy
of a sample of matter.
• measured in K, oF, oC.
Exothermic
Reaction:
Endothermic
Reaction:
• Heat is transferred
from system to
surroundings
• Heat is “absorbed” by
the system
• Heat is “released”
from system
Container gets HOT
• Thermometer
(surroundings) will
absorb heat and will
register a higher
temperature.
Segue: Thermodynamics
• Heat is transferred
from surroundings to
system
• Thermometer
(surroundings) will
release heat and will
register a lower
temperature.
Container gets COLD
Heat (cont.)
• The heat energy {measured in joules (J)} that is
absorbed by an object can be calculated:
Q = m . T . s
Q
= heat lost or gained
m
= mass of the system
T
= change in temperature the system undergoes
s
= specific heat capacity of the system
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Specific Heat Capacity (s)
Definition:
“The amount of heat energy in joules (J) required
to increase the temperature
of 1 gram of a substance by 1oC
Mathematical Formula:
Units:
s = Q/(mT)
J/goC
Specific Heat Capacity
s
(a physical property)
– Metals have low specific heat capacity
(they are easy to heat up)
– Non-metals have higher specific heat capacity
(they are hard to heat up)
– Water has an unusually large specific heat capacity
(it is relatively hard to heat up)
(Joules per gram-degree celsius)
THE END
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