do now: drop off your stuff and head over to banneker for a mini-lab
TRANSCRIPT
Do Now:
Drop off your stuff and head over to Banneker for a mini-lab
Do Now:
1. What are the states of matter?
2. What processes exist that change states of matter?
Do Now (2/22/12):
Please come in quietly and clear your desks of everything except your notecard, writing utensil, and calculator. Thanks!
Do Now:
1. What is a phase change?2. Do we need heat to cause a phase
change?3. Is there a temperature change
during a phase change?
Phase Changes
2/25/11
Brainstorm:
1. What are the states of matter?
2. What processes exist that change states of matter?
States of Matter
Three states of matter: Solid, liquid, and gas
Phase change: any transition between two states of matter
Fusion
Transition from a liquid to a solid state; occurs at the melting point (0˚C for water)
Vaporization
Transition from a liquid to a gaseous state; occurs at the boiling point (100˚C for water)
Melting
Transition from a solid to a liquid state; occurs at the melting point (0˚C for water)
Condensation
Transition from a gaseous state to a liquid state; occurs at the boiling point (100˚C for water)
EvaporationThe random escape of molecules from the surface of a liquid – NOT the same thing as vaporization, which occurs only at 100˚C
Temperature changes
THERE ARE NO TEMPERATURE CHANGES DURING A PHASE CHANGE!!!!!!!
Do Now (2/23/12):
List and describe two of the phase changes we discussed yesterday.
Quizzes look great… keep up the good work!!!
Heat of fusion The amount of heat required to melt 1 kg of a
substance For ice:
Heat required to melt a substance
To freeze a substance, take this amount of heat away
kgJxH f /1034.3 5
fmHQ
Example: Fusion
How much heat is required to freeze 50 kg of ice at 0˚C?
Heat of vaporization The amount of heat required to boil 1 kg of a
substance For water:
Heat required to boil a substance
To condense a substance, take this amount of heat away
kgJxH v /1026.2 6
vmHQ
Example: Vaporization
How much heat is required to boil 50 kg of water at 100˚C?
Phase and Temperature Changes
Please flip to the front of your phase change sheet
Classwork:
Finish one example on your phase change worksheet
Once you have completed that, you may work on your homework.
Classwork:
Finish the front of your phase change worksheet
Once you have completed that, you may begin working on your homework.
Do Now:
How much heat must be added to turn 2 kg of ice at -10˚C to liquid water at 20˚C? *hint – use the back of your phase changes worksheet!
Do Now
How much heat must be added to turn 4 kg of water at 10˚C to water vapor at 120˚C? *hint – use the back of your phase changes worksheet!
Classwork: Finish Heat Diagram activity – make sure ALL
heats are calculated!!! Work on Phase Changes worksheet A or B QUIZ TOMORROW ON PHASE CHANGES AND
HEAT DIAGRAMS!!!!!!
Do Now: 4 kj of heat are added to a 2 kg block of ice at
0˚C. How much ice will melt?
Do Now: How much heat is released to turn 93 kg of
steam at 100˚C to water at 100˚C?
Do NowA: 20 kj of heat are removed from 1.5 kg of ice
initially at -29 ˚C. What is its new temperature?
Do NowB:
A physicist plans to change 0.1 kg of ice at -12 C into 0.1 kg of water at 44C.1. What is the heat required to bring the ice to its
melting point? 2. What is the heat required to melt the ice?
3. What is the heat required to raise the temperature of the melted ice to 44˚C?