11/26/13
• Take Home Exam is Optional
• Clickers turned in on Wednesday 12/4/13
after class.
Suppose you place an ice cube in a cup
of room-temperature water and then
seal it in a well-insulated container. No
energy can enter or leave the container.
If the result were a larger ice cube and some
100oC steam would it violate energy
conservation?
The thermal energy from the water molecules
that have become steam is offset by the
decrease in water molecules that have turned to
ice. Energy is conserved yet we never see a
process like this. Why not?
Gambling
Why do you think you might role Snake Eyes (1/36) but
you never expect the water to get hotter and the ice
cube to get larger?
It’s like saying after a
year of gambling,
the casino will lose.
How Big is Mole?
4 grams of Helium
16 grams of sulfur
29 grams Copper
80 grams of mercury
18 grams or 18 cubic
centimeters of water
6.022 x 1023 molecules
How Big is Mole?
More than the number of throws of craps in Las Vegas
in
A.
B.
C.
D.
E.
1 day
1 year
Your lifetime
Human’s existence
> age of the earth
How Big is Mole?
More than the number of craps throws played in Las
Vegas in
260 tables listed on strip - just in case
A.
B.
C.
D.
E.
1 day
1 year
Your lifetime
Human’s existence
> age of the earth
4,000
10 players per table
1 roll per 22-3 minutes
24 hours
4,000 x 10 x 30 x 24 = 2.88 x 107
2.1 x 1016 days to play 1 moles worth of
craps rolls
6 x 1013 years
Earth is 4.54 billion years old (4.54 x
109)
How Big is Mole?
260 tables listed on strip - just in case 4,000
10 players per table
1 roll per 22-3 minutes
24 hours
4,000 x 10 x 30 x 24 = 2.88 x 107
2.1 x 1016 days to play 1 moles worth of craps
rolls
6 x 1013 years
Earth is 4.54 billion years old (4.54 x 10 9)
How Big is Mole?
More than the number of craps throws played in Las
Vegas in
A.
B.
C.
D.
E.
1 day
1 year
Your lifetime
Human’s existence
> age of the earth
6 x 1013 years
Earth is 4.54 billion years
old
Thermodynamics is all about
probability!!
The Odds ALWAYS win!
Lots of collisions (ice and water) make the water
hotter but lots more make it colder.
Which of the following changes would allow your
refrigerator to use less energy to run? (1)
Increasing the temperature inside the refrigerator;
(2) increasing the temperature of the kitchen; (3)
decreasing the temperature inside the
refrigerator; (4) decreasing the temperature of the
kitchen.
A.
B.
C.
D.
All of the above
1 only
1 and 4
2 and 3
Which of the following changes would allow
your refrigerator to use less energy to run? (1)
Increasing the temperature inside the
refrigerator; (2) increasing the temperature of
the kitchen; (3) decreasing the temperature
inside the refrigerator; (4) decreasing the
temperature of the kitchen.
A.
B.
C.
D.
All of the above
1 only
1 and 4
2 and 3