Phase%20Changes%20

1
Two basic properties of the gas phase are
iRespond Question
Multiple Choice
F
A.) a definite shape and a definite volume
SOLID
B.) a definite shape but no definite volume
C.) no definite shape but a definite volume
LIQUID
D.) no definite shape and no definite volume
E.)
2
Which substance has vibrating particles in
regular, fixed positions?
iRespond Question
Multiple Choice
F
A.) Ca(s)
B.) Hg(l)
C.) Cl2(g)
D.) CaCl2(aq)
E.)
3
The circle on the left shows a magnified view of
a very small portion of liquid water in a closed
container.
iRespond Question
Multiple Choice
F
What would the magnified view show after the
water evaporates?
B.)
C.)
E.)
A.)
D.)
4
Boiling water is a physical change A,B, and D -
Water molecules are not decomposed into hydrogen
and oxygen gas (hydrogen is flammable and oxygen
supports combustion, if these gases were created
there would be explosions every time you boiled
water) C the particles do not vanish (Law of
Conservation of Matter) E when water molecules
boil, they remain water, the particle simply move
farther away from one another
5
Which grouping of the three phases of bromine is
listed in order from left to right for increasing
distance between bromine molecules?
iRespond Question
Multiple Choice
F
A.) gas, liquid, solid
B.) liquid, solid, gas
C.) solid, gas, liquid
D.) solid, liquid, gas
E.)
6
Which phase change is an exothermic process?
iRespond Question
Multiple Choice
F
A.) CO2(s) ? CO2(g)
B.) NH3(g) ? NH3(l)
C.) Cu(s) ? Cu(l)
D.) Hg(l) ? Hg(g)
E.)
7
Which change is exothermic?
iRespond Question
Multiple Choice
F
A.) freezing of water
B.) melting of iron
C.) vaporization of ethanol
D.) sublimation of iodine
E.)
8
A 1.0-gram sample of solid iodine is placed in a
tube and the tube is sealed after all of the air
is removed. The tube and the solid iodine
together weigh 27.0 grams.
iRespond Question
Multiple Choice
F
The tube is then heated until all of the iodine
sublimes and the tube is filled with iodine gas.
Will the weight after heating be
A.) less than 26.0 grams.
Particle mass does not depend on phase
B.) 26.0 grams.
C.) 27.0 grams.
D.) 28.0 grams.
E.) more than 28.0 grams.
9
Assume a beaker of pure water has been boiling
for 30 minutes. What is in the bubbles in the
boiling water?
iRespond Question
Multiple Choice
F
A.) Air
B.) Oxygen gas and hydrogen gas
C.) Oxygen
D.) Water vapor
E.) Heat
10
A glass of cold milk sometimes forms a coat of
water on the outside of the glass (Often referred
to as 'sweat'). How does most of the water get
there?
iRespond Question
Multiple Choice
F
A.) Water evaporates from the milk and condenses
on the outside of the glass.
B.) The glass acts like a semi-permeable membrane
and allows the water to pass, but not the milk.
C.) Water vapor condenses from the air.
D.) The coldness causes oxygen and hydrogen from
the air combine on the glass forming water.
E.)
11
You take a swim in the swimming pool. Although it
is a hot day when you come out, you feel cold.
Which of the following statements is TRUE?
iRespond Question
Multiple Choice
F
A.) The water in the pool is warmer than the air
B.) The water in the pool is colder than the air
C.) The water on your skin gets cold when you
step out of the pool
D.) The water on your skin evaporates
L ? G is endothermic, absorbing heat energy from
your body
E.)
12
At which temperature will equilibrium exist for
the system below? H2O(s) ? H2O(l)
iRespond Question
Multiple Choice
F
A.) 0 K
B.) 100 K
C.) 273 K
D.) 373 K
E.)
13
A pot of water is brought to a boil. The
temperature of the water when it started to boil
was 100.0ºC. What do you expect the thermometer
to read after boiling for 15 minutes?
iRespond Question
Multiple Choice
F
A.) Below 100.0ºC
B.) 100.0ºC
C.) 105.0ºC
D.) 115.0ºC
E.) Above 115.0ºC
14
As a solid substance absorbs heat at its melting
point, the melting point will
iRespond Question
Multiple Choice
F
A.) decrease
B.) increase
C.) remain the same
D.)
E.)
15
The graph represents the uniform heating of a
solid, starting below its melting point. Which
portion of the graph shows the solid and liquid
phases of the substance existing in equilibrium?
iRespond Question
Multiple Choice
F
A.) AB
S
B.) BC
S,L
C.) CD
L
D.) DE
L,G
E.) EF
E.)
G
16
iRespond Question
Multiple Choice
F
The graph shown represents the relationship
between temperature and time as heat is added
uniformly to a substance, starting when the
substance is a solid below its melting point.
Which portions of the graph represent times when
heat is absorbed and potential energy increases
while kinetic energy remains constant?
A.) A and B
B.) B and D
C.) A and C
D.) C and D
Potential energy changes when temperature (KE)
does not
E.)
17
The graph represents the uniform cooling of a
substance, starting with the substance as a gas
above its boiling point. During which interval is
the substance completely in the liquid phase?
iRespond Question
Multiple Choice
F
A.) AB
G
B.) BC
G,L
C.) CD
L
D.) DE
L,S
E.)
18
iRespond Question
Multiple Choice
F
The graph (see image) represents the uniform
heating of a substance, starting with the
substance as a solid below its melting
point. Which line segment represents an increase
in potential energy and no change in average
kinetic energy?
Temperature (KE) changes on the slants, Potential
Energy on the Plateus
A) 1 B) 2 C) 3 D) 4
E.)
A.) 1
C.) 3
D.) 4
B.) 2
19
As ice melts at standard pressure, its
temperature remains at 0ºC until it has
completely melted. Its potential energy
iRespond Question
Multiple Choice
F
A.) decreases
B.) increases
C.) remains the same
D.)
The particles move further apart, but the kinetic
energy remains the same
E.)
20
The heat of fusion is defined as the energy
required at constant temperature to change 1 unit
mass of a
iRespond Question
Multiple Choice
F
A.) gas to a liquid
B.) gas to a solid
C.) solid to a gas
D.) solid to a liquid
Melting/Fusion
E.)
21
In which equation does the term "heat" represent
heat of fusion?
iRespond Question
Multiple Choice
F
Heat of Vaporization

1. 1
2. 2
3. 3
4. 4

E.)
A.) 1
B.) 2
C.) 3
D.) 4
22
What amount of heat is required to completely
melt a 29.95 gram sample of H2O(s) at 0ºC?
iRespond Question
Multiple Choice
F
A.) 334 J
Q mHfus (29.95g)(334J/g)
B.) 2260 J
C.) 1.00 103 J
D.) 1.00 104 J
E.)
23
How much energy is released when 36.0 grams of
steam condenses into liquid water?
iRespond Question
Multiple Choice
F
A.) 12.0 kJ
Q mHvap (36.0g)(2260J/g)
B.) 81.4 kJ
C.) 195 kJ
D.) 1580 kJ
E.)
24
How many joules are needed to vaporize 2.00 g of
liquid ethanol at its boiling point, 78.0ºC? (The
heat of vaporization for ethanol is 854 J/g)
iRespond Question
Multiple Choice
F
A.) 156
Q mHvap (2.00g)(854J/g) Temperature is
not included as this is a phase change (it will
remain at 78)
B.) 540
C.) 854
D.) 1710
E.)
25
As the temperature of a liquid increases, its
vapor pressure
iRespond Question
Multiple Choice
F
A.) decreases
B.) increases
C.) remains the same
D.)
E.)
26
As the pressure on the surface of a liquid
decreases (atmospheric pressure), the temperature
at which the liquid will boil
iRespond Question
Multiple Choice
F
A.) decreases
B.) increases
C.) remains the same
The atmospheric pressure is lower, meaning that
the vapor pressure will be lower, and will cause
boiling to occur at a lower temperature
D.)
E.)