ENERGY AND HEAT
Chemical Reactions,
Energy, Heat, Specific
Heat, & Calorimetry
N. Paes
TABLE OF CONTENTS
Energy
Potential & Kinetic
Chemical Potential Energy
Heat
Conduction, Convection, & Radiation
Specific Heat
Calorimeter
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ENERGY AND HEAT
OBJECTIVE
SWBAT (I CAN): describe and
calculate heat, mass,
temperature change, and
specific heat
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ENERGY AND HEAT
DISCUSSION QUESTIONS
How do you think heat
and energy are related?
ANSWER HERE:
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ENERGY
Energy is the capacity to do work or
produce heat
● 2 Types: potential and kinetic energy.
Potential energy is stored energy, due to
the composition or position
Kinetic energy is energy of motion
Buthelezi, T. (2015). Chemistry: Matter & change. Columbus, OH: McGraw-Hill Education.
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DISCUSSION QUESTION
Question: What do you think is an example
of potential energy? Explain.
ANSWER:
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CHEMICAL POTENTIAL ENERGY
Chemical systems contain both kinetic and
potential energy.
Chemical potential energy is energy stored in
chemical bonds of a substance by the
arrangement of the atoms and molecules.
Chemical potential energy is released or
absorbed as heat during chemical processes or
reactions.
Buthelezi, T. (2015). Chemistry: Matter & change. Columbus, OH: McGraw-Hill Education.
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HEAT
Often, chemical potential energy is
released as heat. Heat is thermal energy
that flows from warmer objects to cooler
objects.
When a warmer object loses energy, its
temperature decreases, when a cooler
object absorbs energy, its temperature
rises.
Buthelezi, T. (2015). Chemistry: Matter & change. Columbus, OH: McGraw-Hill Education.
N. Paes
DISCUSSION QUESTION
Question: Which direction do you think
heat flows?
ANSWER:
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HEAT TRANSFER
Heat can be transferred by three processesconduction, convection, and radiation.
● Conduction is the transfer of thermal energy that
occurs when particles collide (objects are touching).
● Heating caused by the motion of fluid in a liquid or
gas due to temperature differences is called
convection.
● Radiation is the transfer of energy by
electromagnetic waves, such as how the sun warms
earth.
Buthelezi, T. (2015). Chemistry: Matter & change. Columbus, OH: McGraw-Hill Education.
N. Paes
DISCUSSION QUESTION
Question: What do you think is an example
of convection?
ANSWER:
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DISCUSSION QUESTION
Question: What do you think is an example
of radiation?
ANSWER:
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ENERGY AND HEAT
The specific heat of any substance is the amount of
heat required to raise the temperature of one gram
of that substance by one degree Celsius.
Because different substances have different
compositions, each substance has its own specific
heat.
To raise the temperature of water by one degree
Celsius requires more energy than to raise the
temperature of an equal mass of concrete.
Buthelezi, T. (2015). Chemistry: Matter & change. Columbus, OH: McGraw-Hill Education.
N. Paes
DISCUSSION QUESTION
Question:Why do you think it requires more
energy to heat water than concrete?
ANSWER:
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CALCULATING HEAT
The quantity of heat absorbed or released by a
substance is equal to the product of its specific
heat, the mass of the substance, and its change
in temperature.
q= c x m x ΔT
q represents the heat absorbed or released,
c represents the specific heat of the substance,
m represents the mass of the sample in grams,
and ΔT is the change in temperature in Celsius.
Buthelezi, T. (2015). Chemistry: Matter & change. Columbus, OH: McGraw-Hill Education.
N. Paes
CALORIMETRY
A calorimeter is an insulated device used for
measuring the amount of heat absorbed or
released during a chemical or physical process.
A known amount of water is placed in an
insulated chamber to absorb the energy
released from the reacting system or to provide
the energy absorbed by the system.
Buthelezi, T. (2015). Chemistry: Matter & change. Columbus, OH: McGraw-Hill Education.
N. Paes
DISCUSSION QUESTION
Question: Why do you think calorimeters
are insulated?
ANSWER:
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ENERGY AND HEAT
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ENERGY AND HEAT
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ONLINE SIMULATION
Energy Forms and Changes
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ENERGY AND HEAT
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ENERGY AND HEAT
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REFERENCES
Buthelezi, T. (2015). Chemistry: Matter &
Change. Columbus, OH: McGraw-Hill
Education.
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