Phase changes pogil - idek PDF

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Name: ___________________________________________________

Physical Behavior of Matter Heating and Cooling Curves OBJECTIVES:  Be able to distinguish between molecules in each phase of matter  Predict phases of matter by location on a heating/cooling curve graph  Create a cooling curve when given data and identify phase changes, E changes Model 1 represents molecules in the three phases of matter. Based on what you already know about these phases, complete the table that follows. A word bank has been provided for the last column.

MODEL 1: PHASE CHANGE PARTICLE DIAGRAM Word Bank for Column 3: Gas

Melting/Fusion Condensation

COLUMN 1 PARTICLE DIAGRAM A PARTICLE DIAGRAM B PARTICLE DIAGRAM C

Dporization

Solid

COLUMN 2 DESCRIBE THE PARTICLE DIAGRAM

G

IS HEAT BEING ADDED OR RELEASED (TAKEN AWAY)? ARROW D (FROM A TO B) ARROW E (FROM B TO C) ARROW F (FROM C TO B) ARROW G (FROM B TO A)

E eezing

Liquid

COLUMN 3 WHAT PHASE IS THIS?

F

WHAT PROCESS (PHASE CHANGE) IS OCCURING?

Look at the word ENDOTHERMIC. Based on the prefix endo-, do you think energy is being added (entering), or being released (exiting)? ____________________________________________________________ Which phase change processes indicate an ENDOTHERMIC reaction? ________________________________ Look at the word EXOTHERMIC. Based on the prefix exo-, do you think energy is being added (entering), or being released (exiting)? ____________________________________________________________ Which phase change processes indicate an EXOTHERMIC reaction? __________________________________

MODEL 2: HEATING CURVE GRAPH The following graph shows what happens to water as it goes from ice to liquid water to water vapor. Use the word bank and heating curve graph below to identify these phases and phase chang

WORD BANK

Temperature Time Solid Liquid Boiling/Vaporization Point

Melting/Freezing Point Gas

3.

Y axis Label:

2.

1.

X axis Label:

Now draw a particle diagram for locations 1, 2, and 3 on the heat curve. **Remember that you are drawing these particle diagrams for WATER** Par t i c l edi agr am #1

Par t i c l edi agr am #2

Par t i c l edi agr am #3

How do the particles in a solid, liquid and gas differ? ______________________________________________________________ __________________________________________________________________________________________ _____________________________ Now check your answers with this graph. Then use this graph to answer the questions that follow.

1. During which line segment(s) does temperature increase? _______________________________________________________ 2. During which line segment(s) is there no change in temperature? _______________________________________________ 3. If this substance were water, at what temperature would segment B – C occur? _______________________________

4. If this substance were water, at what temperature would segment D – E occur? _______________________________ 5. Kinetic energy is the energy of motion. It can be used interchangeably with the word temperature. Which line segment(s) show an increase in kinetic energy? ___________________________________________________________ 6. Potential energy is stored energy. When kinetic energy is not increasing, but heat is still being added to the system this potential energy increases. Which line segment(s) show this? __________________________________ 7. Compare segments B – C and D – E. Why is segment D – E is longer than B – C? _______________________________________________________________________________________

BIG IDEA - As temperature increases, substances go from the ______________________ to the _________________________ to the __________________________ phase. This shows an increase in _________________________ energy. - Potential energy increases when a substance is ___________________________ and ____________________________. These are _____________________________ reactions because energy is being added.

Here are the heating curves for 4 different substances. Use these curves to answer the questions that follow. Heat Curve for Cl2

Heating Curve of Water

150

50 0 -50 0

5

10

15

20

25

30

-100 -150

Tempersture (oC)

Temperature (oC)

100

-200 -250

250 200 150 100 50 0 -50 0 -100 -150 -200 -250

2000

Temperature (oC)

Temperature (oC)

2500

1500 1000 500 0 10

15

20

15

20

25

30

25

30

Heating Curve For Gold

Heating Curve for NaCl

5

10

Time (min)/Heat Added

Time (min)/Heat Added

0

5

25

30

4500 4000 3500 3000 2500 2000 1500 1000 500 0 -500 0

Time (min)/Heat Added

5

10

15

20

Time (min)/Heat added

1. Which substance does have the highest boiling point? _______________________________ What is that boiling point of this substance? _____________________ 2. At what temperature range is NaCl a solid? _____________________________ 3. What is the melting point for Cl2? ________________________________________ 4. Which substance is a liquid at room temperature? _________________________________ 5. What phase is Cl2 in at room temperature? _________________________________________ 6. What is NaCl’s boiling point? _________________________________________ 7. What phase is water in at -100˚C? ____________________________________ 8. What temperature is Cl2 at after being heated for 20 minutes? ______________________________________ 9. Draw a particle diagram for Cl2 at temperatur

10.

Draw a particle diagram of NaCl at a temp

500˚C.

You will now take what you have learned and infer that knowledge to create a Cooling Curve. A cooling curve is simply the opposite of a heating curve- instead of temperature INCREASING, it is DECREASING. Use the information below to create this Cooling Curve for the unknown substance.

TEMPERATURE

-A sample of a substance is cooled from a temperature of 250°C to 10°C over a period of two hours. -The boiling point of the substance is 175°C and the melting point is 22°C.

TIME Now clearly label the following items in the appropriate locations. (KE= kinetic energy, PE= potential energy) Solid Liquid Gas Condensation Boiling Freezing Point Melting Point Fusion KE changing KE not changing PE changing PE not changing

BIG IDEA - As temperature decreases, substances go from the ______________________ to the _________________________ to the __________________________ phase. This shows an decrease in _________________________ energy. - Potential energy increases when a substance is ___________________________ and ____________________________. These are _____________________________ reactions because energy is being released.

Putting it all together:

1

3 2

1. Fill in the arrows with the missing information from the particle diagrams above. 1: ______________________________________________________2: _____________________________________________________ 3: _____________________________________________________ 4: _____________________________________________________ 2. Which statement correctly describes the energy of the particle during interval BC? (a) Potential energy decreases and average kinetic energy incr (b) Potential energy increases and average kinetic energy incre (c) Potential energy increases and average kinetic energy rema (d) Potential energy remains the same and average kinetic ene

3.

Which line segment is a liquid, only? __________________

Use the following graph to help you answer questions 4 and 5. The graph below represents the uniform heating of a substance, starting with the substance as a solid below its melting point.

4. Which line segment represents an increase in potential energy and no change in average kinetic energy? (a) (b) (c) (d) 5. CIRCLE ONE: This graph represents an ( endothermic reaction.

/

exothermic

)

Some portions of this pogil were authored by: Erin Graham; Revised by: Josephine Parlagreco, Lizabeth Tumminello Edited by Linda Padwa and David Hanson, Stony Brook University. Regents questions from June 2009 NYS exam. Heating Curves from GCSD website....