1.1.1 Thermodynamics

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1.1.1 Thermodynamics

• Unit 1

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Energy

• Energy is the ability to do work or produce heat
• Thermodynamics is the production of heat

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Thermal Energy

• Molecules and atoms that make up all substances
  are constantly in motion- this motion is called
  kinetic energy
• Thermal energy is related to kinetic energy
• Molecular motion increase as temperature
  increases?
• Demo. of thermal energy-
• Rub hands together

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Thermal Energy cont

• Heat is also the flow of energy (always from a
  hotter substance to a colder one)
• Example- hold an ice cube in your hand- what
  happens?
• Heat from your hand is transferred to the ice
  cube, which then melts
• Spraying water on crops to prevent frost

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Law of Conservation of Energy

• First Law
• Energy is never created nor destroyed, it only
  changes form
• Ex- when gas is burned in your car, bond energy
  is converted into kinetic energy (moving pistons)
  and heat
• Chemical reactions typically involve potential
  energy being converted into kinetic energy

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Heat energy and Temperature

• Heat- is the amount of kinetic energy in a sample
  of matter
• Flows from warmer to cooler objects
• Unit of heat is the Joule (J)
• FYI-
• one joule of energy is equal to the amount of
  energy used by a 100W bulb for 0.01 s
• An ordinary paper match burns about 1,000 J
• Another unit is the calorie (cal)

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Temperature

• Temperature is a measure of the average kinetic
  energy
• Units are in degrees celsius (oC) or in Kelvins
  (K)
• To convert between oC and K
• oC 273-K K oC273
• Assignment converting Kelvin to celsius

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Lab Activity

• Lab
• Purpose understand the relationship between
  kinetic energy and temperature and potential and
  kinetic energy during phase changes
• Phase changes
• Heating curve of water

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Kinetic Energy Curves

• In any substance, all of the atoms are in
  constant motion
• However, not all molecules will have the same
  energy- some will be moving fast, some slow and
  some in between
• If we were to graph this it would be a bell graph

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Kinetic energy Curve

• http//www.saskschools.ca/curr_content/chem30_05/1
  _energy/energy1_4.htm
• http//www.online.bcelearner.ca/file.php/11/course
  _material/unit1/U01L06.htm - for analogy

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• Something to think about
• What has more heat energy an iceberg or a cup of
  boiling water?
• An iceberg because there are many more molecules
  in an iceberg than a cup of water heat is the
  TOTAL kinetic energy therefore more molecules
  means more energy

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