1. Burn, baby, burn: An introduction to energy
Unit 3 Thermodynamics: Zumdahl Chapters 6 and 17

2. Pre-Studying before 1st class

3. In this unit…and more! Why do explosions happen?
Why is Rome’s weather so temperate?
Why does the floor feel SO cold in the morning?
In this unit…and more!

4. The ability to do work or produce heat
What is Energy?

5. Potential Energy Energy of position
Think: what is the “potential” to do damage?
Which ball has more
potential energy?
Green ball! Higher up
Potential Energy

6. Kinetic Energy Energy of motion Chemical reactions KE = ½ mv2
Light, heat, sound, physical movement
Chemical reactions
Use and give off energy
Give off heat, light, sound
Use energy to break and
make bonds
KE = ½ mv2
Kinetic Energy

7. Energy changes over time

8. WRONG!
Heat flows
HOT  COLD
You’ll let the cold in!

9. How is heat transferred?

10. Thermal equilibrium: Heat flows until the temperatures in each object are the same
A: when all temperatures are equal (equilibrium)
When does the heat stop?

11. Laws of Thermodynamics
First law: Energy is conserved in a system
Heat in = Heat out
Second law: Energy wants to disperse (come to thermal equilibrium)
Heat won’t “bunch” up in one place – it always spreads by molecule movement!
These concepts relate to KMT from our gases unit quite a bit!
Laws of Thermodynamics

12. The big idea Endothermic versus Exothermic
Chemical reactions are all about energy in and out (enthalpy)!
Bonds breaking = requires energy IN
Bonds forming = energy OUT
Part 2 of the unit
The big idea

13. Heat = total KINETIC ENERGY transferred from one object to another
NOT a substance. Just energy moving.
Temperature = how much ENERGY an object’s molecules have on average
How fast are the particles moving on average?
Video Clip
What is heat?

14. q in = q out 1st law: Energy is conserved in a system
If something cold is mixed with something warm, thermal equilibrium is reached.
The energy (heat) given from the warm object is equal to the energy taken by the cold object!
q in = q out

15. Joule = (SI unit of energy) work to move an object 1 meter with 1 Newton of force
Work energy is related to heat energy
Think friction!
calorie = energy needed to raise 1 gram of water 1 degree Celsius
Relationship between:
1 calorie = Joules
James Prescott Joule
Units of Energy

16. If you have 4.0 grams of water, how many calories are required to raise the temperature 2.0 degrees Celsius?
How many Joules is that?
8 calories! Or 33.4 Joules.
Practice it!

17. STOP HERE.

18. Warm-up (10/31) Lab 7 out on desk for me to see while you…
Get a Lab 8 Handout and READ THE INTRODUCTION CAREFULLY
Then pre-lab question in your lab book (along with purpose, etc)
Warm-up (10/31)

19. In this unit…and more! Why do explosions happen?
Why is Rome’s weather so temperate?
Why does the floor feel SO cold in the morning?
In this unit…and more!

20. The ability to do work or produce heat
What is Energy?

21. q in = q out 1st law: Energy is conserved in a system
If something cold is mixed with something warm, thermal equilibrium is reached.
The energy (heat) given from the warm object is equal to the energy taken by the cold object!
q in = q out

22. Demos – every material is different!
Every material (rock, bone, brass, dirt, air) has its own ability to store heat!
Called heat capacity
Specific heat capacity = how much heat (in Joules) does it take to raise 1 gram of that substance 1 degree Celsius?
demos: ice cube on wood and metal, hands on tongs, etc
Demos – every material is different!

23. q = mcΔT q = total heat transferred to or from (J)
m = mass of the substance (g)
c = heat capacity (J/g°C)
How many Joules does it take to raise 1 gram of the substance 1 degree Celsius?
c of water = J/g°C
ΔT = absolute value of change in temperature in the system (K or °C)
q = mcΔT

24. Calorimetry! Standard Calorimeter Bomb Calorimeter
Coffee Cup Calorimeter
Calorimetry!

25. Unknown Heat Capacity Lab #8

26. q lost by metal = q gained by water
How to do it:
Calculate the specific heat capacity (c) for the metal using the ΔT and mass of the metal and the ΔT, of water, and mass of the water
Only one unknown variable! (Cmetal)
q lost by metal = q gained by water
m c ΔT = m c ΔT

27. HOMEWORK DAY 1 Read Ch 6.1-6.2 Lab 8 Post Lab due Friday in class
Great video (Prof Dave) on our lab and heat flow
Crash Course Hank again 
Lab 8 Post Lab due Friday in class
Make sure you review the first part of this ppt (content you learned at home) and add anything to notes
HOMEWORK DAY 1