WorksheetsPhase Changes & Diagrams
Total questions: 40
Worksheet time: 21mins
Name
Class
Date
1.
Water exists as a _____________ at 3 mmHg and 50 °C.
a)
solid
b)
liquid
c)
gas
d)
supercritical fluid
2.
Water exists as a _____________ at 700 mmHg and 50 °C.
a)
solid
b)
liquid
c)
gas
d)
supercritical fluid
3.
Water exists as a _____________ at 3 mmHg and 50 °C.
a)
solid
b)
liquid
c)
gas
d)
supercritical fluid
4.
Water exists as a _____________ at 700 mmHg and 50 °C.
a)
solid
b)
liquid
c)
gas
d)
supercritical fluid
5.
What phase change(s) may occur at pressures below 4.58 mmHg?
a)
sublimation/deposition
b)
melting/freezing
c)
all phase changes are possible at these pressures
d)
vaporization/condensation
6.
The pressure is increased on a sample of water at 0 °C from 0 mmHg to 800 mmHg. In order, what changes occur?
a)
deposition, melting
b)
sublimation, melting
c)
condensation, freezing
d)
deposition, freezing
7.
Based on this phase diagram, which state is the most dense?
a)
gas
b)
solid
c)
liquid
d)
solid and liquid have equal densities
8.
Water will boil at temperatures above 100 °C at pressures __________ 760 mmHg.
a)
below
b)
above
c)
equal to
d)
significantly below
9.
Which statement is true for carbon dioxide at -60 °C?
a)
All three phases are possible.
b)
It can exist as a solid or a gas, depending on pressure.
c)
It is a solid.
d)
With enough pressure it can be melted.
10.
Based on its phase diagram, which is the most dense state for CO2?
a)
gas
b)
liquid
c)
solid
d)
supercritical fluid
11.
What is true regarding CO2 for temperatures above 31 °C?
a)
It can never be liquified.
b)
It decomposes.
c)
It has a high pressure.
d)
It is a plasma.
12.
At 10 atm, dry ice is heated from -100 °C to 30 °C. What changes occur?
a)
freezing, then condensation
b)
melting only
c)
sublimation only
d)
melting, then boiling
13.
What is the normal melting point of CO2?
a)
-78.5 °C
b)
-56.7 °C
c)
31 °C
d)
It doesn't have a normal melting point.
14.
What is the normal boiling point of CO2?
a)
-78.5 °C
b)
-56.7 °C
c)
31 °C
d)
It doesn't have a normal boiling point.
15.
What state of matter is X?
a)
solid
b)
liquid
c)
gas
d)
supercritical fluid
16.
What state of matter is Y?
a)
solid
b)
liquid
c)
gas
d)
supercritical fluid
17.
What state of matter is Z?
a)
solid
b)
liquid
c)
gas
d)
supercritical fluid
18.
What change occurs from F to E?
a)
sublimation
b)
deposition
c)
melting
d)
condensation
19.
What change occurs from E to C?
a)
sublimation
b)
freezing
c)
melting
d)
boiling
20.
What change occurs from C to D?
a)
condensation
b)
vaporization
c)
melting
d)
sublimation
21.
What is the normal boiling point of this substance?
a)
150 °C
b)
100 °C
c)
-50 °C
d)
0 °C
22.
What is the normal melting point of this substance?
a)
150 °C
b)
100 °C
c)
-50 °C
d)
0 °C
23.
What is point A?
a)
triple point
b)
critical point
c)
equilibrium point
d)
normal melting point
24.
What is point B?
a)
triple point
b)
critical point
c)
equilibrium point
d)
normal melting point
25.
Above the temperature of point B, this substance exists as a ____________.
a)
solid
b)
liquid
c)
gas
d)
supercritical fluid
26.
Below the temperature of point B, this substance can exist as a ____________.
a)
solid only
b)
liquid only
c)
gas only
d)
either a solid, liquid or gas
27.
At 0.10 atm, what phase(s) can exist?
a)
solid, liquid or gas
b)
liquid or gas
c)
solid only
d)
gas only
28.
Temperature is a measure of the average _____________ energy of the particles of a substance.
a)
potential
b)
kinetic
c)
gravitational
d)
heat
29.
The slower molecules move,
a)
the higher the temperature
b)
the less temperature
c)
the same temperature
d)
I don't know
30.
The faster molecules move,
a)
the higher the temperature
b)
the less temperature
c)
the same temperature
d)
I don't know
31.
Between which points is the temperature of the substance remaining constant?
a)
A-B only.
b)
A-B, C-D, E-F
c)
B-C only.
d)
B-C, D-E
32.
Between which points is the temperature of the substance increasing?
a)
A-B only.
b)
A-B, C-D, E-F
c)
B-C only.
d)
B-C, D-E
33.
A substance's heating curve is shown in the graph. What is its boiling point?
a)
100 C
b)
60 C
c)
80 C
d)
20 C
34.
True or false: melting and freezing occur at the same temperature!
a)
True
b)
False
c)
I don't know
35.
In which region(s) of the graph does a phase change occur?
a)
Region 1, 3, & 5
b)
Region 2 & 4
c)
Region 1 only
d)
Region 1 & 2
36.
In an exothermic phase transition, heat energy is transferred from the system to its surroundings
a)
True
b)
False
37.
During an endothermic phase transition, more heat energy is added to the system
a)
True
b)
False
38.
Bonus Question: What change occurs from D to C?
a)
condensation
b)
vaporization
c)
melting
d)
sublimation
39.
What line segment represents only the solid state?
a)
A-B
b)
B-C
c)
C-D
d)
D-E
40.
Which process takes the longest to occur?
a)
melting
b)
boiling
c)
freezing
d)
heating the solid
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