Chem I – Solids & Liquids
#1 – Phase Diagrams
Name_________________________ Period_______
45 Points
Heating Curve
A heating curve is a graph that represents a substance’s change from solid to gas.
1. Label the graph (section #1 to #5) with the appropriate phase.
2. As a substance goes through section (2), what happens to the distance between the particles?
__________________________
3. What is the name of the process happening during section (4)? _______________
4. What would be the name of the process happening during section (4) if time were going the other
way? __________________________
5. What is the melting point of this substance? ________________
6. When this substance is melting, the temperature of the ice-water mixture remains constant
because (multiple choice):
a. Heat is not being absorbed
b. The ice is colder that the water
c. Heat energy is being converted to potential energy by breaking bonds in the solid
d. Heat energy is being converted to kinetic energy by breaking bonds in the solid
7. What is the boiling point of the substance?
8. Which number represents heating of the solid? _______
9. Which number represents heating of the vapor? ________
1
Triple Point Phase Diagram
A triple point diagram is a graph that represents a substance’s phases
at varying pressures and temperatures
e
1.0
Pressure (atm)
C
A
d
0.5
B
100
o
120
o
200 220
o
o
Temperature (oC)
Answer the following questions using the chart above.
1. What section represents the solid phase?
_______________
2. What section represents the liquid phase?
_______________
3. What section represents the gas phase?
_______________
4. What letter represents the triple point?
_______________
5. Define triple point: _______________________________________________________
6. What letter represents the critical point?
_______________
7. Define critical point:_______________________________________________________
8. What is the substance’s normal melting point (at 1atm)?
_______________
9. What is the substance’s normal boiling point (at 1 atm)?
_______________
10. Above what temperature is it impossible to liquefy this substance no matter what
the pressure? _______________
11. At what temperature and pressure do all three phases coexist?
__________________
12. Is the density of the solid greater than or less than the density of the liquid? __________
13. Would an increase in pressure cause this substance to freeze or melt?
2
_________
Chem I – Solids & Liquids
#2 - Phase Review
PART A: Label the Diagram
1. Label the following diagram indicating the following phases. Write the phase next to the
letters (a through e).
solid
solid/liquid
liquid
gas/liquid
gas
2. Label the following diagram indicating the following points. Write the name on the graph and
point out its location by using an arrow.
freezing point
vaporization point
condensation point
Temperature oC
melting point
PART B: Answer the following questions using the chart above.
1. What is the freezing point (temperature) of the substance?
_______________
2. What is the boiling point (temperature) of the substance?
_______________
3. What is the melting point (temperature) of the substance?
_______________
4. What letter represents the range where the solid is being warmed?
_______________
5. What letter represents the range where the liquid is being warmed?
_______________
6. What letter represents the range where the vapor is being warmed?
_______________
7. What letter represents the melting of the solid?
_______________
8. What letter represents the vaporization of the liquid?
_______________
9. What letter(s) show a change in potential energy?
_______________
10. What letter(s) show a change in kinetic energy?
_______________
11. What letter represents condensation?
_______________
12. What letter represents crystallization?
_______________
3
Phase Diagram
e
Pressure (atm)
1.0
C
A
d
0.5
B
45
o
60
100 110
o
o
o
Temperature (oC)
PART C: Color and label the following areas of the graph.

Color the solid area (RED), the liquid area (YELLOW) and gas area (GREEN)
PART D: Answer the following questions using the chart above.
14. What section represents the solid phase?
_______________
15. What section represents the liquid phase?
_______________
16. What section represents the gas phase?
_______________
17. What letter represents the triple point?
_______________
18. Define triple point:
_______________________________________________________
19. What letter represents the critical point?
20. Define critical point:
_______________
_______________________________________________________
21. What is the substance’s normal melting point (at 1atm)?
_______________
22. What is the substance’s normal boiling point (at 1 atm)?
_______________
23. Above what temperature is it impossible to liquefy this substance no matter what
the pressure?
_______________
24. At what temperature and pressure do all three phases coexist?
_______________
25. Is the density of the solid greater than or less than the density of the liquid? _______________
26. Would an increase in pressure cause this substance to freeze or melt?
4
_______________
PART E: Define the following (from the following word bank):





heating curve
allotrope
triple point
boiling point
freezing point





sublimation
capillary action
cohesion
melting point
adhesion





surface tension
condensation
unit cell
triple point diagram
amorphous solid
1. Graph that represents a substance’s change from solid to gas.
2. Temperature in which a liquid becomes a gas.
3. Substances that do not have a definite melting point, viscosity.
4. Temperature in which a solid becomes a liquid.
5. The attraction of liquid molecules for other surfaces.
6. The force at the surface of a liquid due mostly to cohesive forces.
7. The movement of a liquid up a tube due mostly to adhesive forces.
8. Substances with same chemical formulas but different states.
9. The attraction of liquid molecules for each other.
10. Temperature in which a liquid becomes a solid.
11. The phase change in which a solid becomes a gas.
12. The phase change in which a gas becomes a liquid.
13. The smallest component of a crystal.
14. The pressure and temperature in which all three phases of diagram matter for a
substance to exist in equilibrium.
15. A graph that represents a substance’s phases at varying pressures and temperatures.
5
Chem I – Solids & Liquids
#3 - Le Chatlier’s Ship – Equilibrium
Lean to the left! Shift to the right! Evaluate the changes to the following phase changes
equilibriums. Decide if the stress will cause the reaction to shift to the left, or shift to the
right. Compare the total number of left shifts to the total number of right shifts to decide if
LeChatlier’s Ship will sink to the left, sink to the right or stay afloat.
Directions: Place an arrow pointing right (if the shift is toward the product side) or an arrow
pointing to the left (if the shift is toward the reactant side).
Equilibrium Equation
Stress Applied
1
gas ↔ heat + liquid
Add more gas
2
heat + solid ↔ liquid
Lower the temperature
3
solid + heat ↔ liquid
Remove heat
4
heat + liquid ↔ gas
Add liquid
5
gas ↔ heat + liquid
Add liquid
6
liquid ↔ heat + solid
Raise the temperature
7
heat + liquid ↔ gas
Remove heat
8
heat + solid ↔ liquid
Remove liquid
9
gas ↔ heat + liquid
Remove liquid
10
liquid ↔ heat + solid
Add solid
11
gas ↔ liquid + heat
Lower the temperature
12
liquid ↔ heat + solid
Add liquid
13
heat + liquid ↔ gas
Raise the temperature
14
heat + solid ↔ liquid
Add heat
15
gas ↔ liquid + heat
Remove gas
Continued…
6
Shift
Equilibrium Equation
Stress Applied
16
gas ↔ liquid + heat
Add heat
17
liquid ↔ solid + heat
Remove solid
18
heat + liquid ↔ gas
Add heat
19
solid + heat ↔ liquid
Add solid
20
liquid ↔ heat + solid
Remove heat
21
gas ↔ liquid + heat
Increase the temperature
22
heat + solid ↔ liquid
Add liquid
23
heat + liquid ↔ gas
Remove liquid
24
liquid ↔ heat + solid
Add heat
25
solid + heat ↔ liquid
Increase temperature
26
heat + liquid ↔ gas
Remove gas
27
gas ↔ heat + liquid
Remove heat
28
liquid ↔ heat + solid
Lower the temperature
29
heat + liquid ↔ gas
Add gas
30
heat + solid ↔ liquid
Remove solid
31
liquid ↔ solid + heat
Remove liquid
32
gas ↔ liquid + heat
Lower the temperature
Shift
Number of shifts to the left __________________
Number of shifts to the right _________________
What happens to LeChatlier’s Ship? _____________________________________
7
Chem I – Solids & Liquids
#4 - Le Chatlier’s Principle
Le Chatilier’s Principle states that when a system at equilibrium is subjected to a stress, the system will shift its
equilibrium point in order to relieve the stress.
Complete the following chart by placing an arrow pointing left, right or writing ‘none’ for equilibrium shift, and
place an arrow pointing down (decreases), up (increases) or state ‘same’ for the concentrations of reactants and
products, and for the value of K.
N2(g) + 3H2(g) ↔ 2NH3(g) + 22.0 kcal
Stress
1. Add N2
Equilibrium
Shift
[N2]
[H2]
[NH3]
K
→
↑
↓
↓
↑
Same
2. Add H2
3. Add NH3
4. Remove N2
5. Remove H2
6. Remove NH3
7.
Increase
Temperature
8. Decrease
Temperature
9.
Increase
Pressure
10. Decrease
Pressure
8
12.6 kcal + H2(g) + I2(g) ↔ 2HI(g)
Stress
1.
Add H2
Equilibrium
Shift
[H2]
[I2]
[HI]
K
→
↑
↓
↓
↑
Same
2. Add I2
3.
Add HI
4. Remove H2
5. Remove I2
6.
Remove HI
7.
Increase
Temperature
8. Decrease
Temperature
9. Increase
Pressure
10. Decrease
Pressure
NaOH(s) ↔ Na+(aq) + OH-(aq) + 10.6 kcal
(remember that pure solids and liquids do not affect equilibrium values)
Stress
1.
Equilibrium
Shift
[NaOH]
[Na+]
Add NaOH(s)
2. Add NaCl
(adds Na+)
3.
Add HI
(adds OH-)
4.
Add H+
(removes OH-)
5.
Increase
Temperature
6.
Decrease
Temperature
7.
Increase
Pressure
8. Decrease
Pressure
9
[OH-]
K