Unit 7
Name _______________________________ # ________
Section 1: Phases of Matter
1. What are the characteristics of a solid?
2. What are the characteristics of a liquid?
3. What are the characteristics of a gas?
4. Label the pictures below as solid, liquid, or gas.
__________
__________
____________
Section 2: Density
You will watch a few minutes of “Raiders of the Lost Ark.” If you haven’t seen
this movie before, here’s the background:
Indiana Jones (the guy in the hat) is an archaeologist, trying to take a statue
from some ruins. The ruins are booby-trapped. The statue is on a platform,
which is apparently sensitive to the weight of the statue. (If the statue is
removed, a trap will go off.)
1. The density of gold is 19.3 g/mL. If the statue is solid gold and has a volume
of 1 L, how much is the mass of the statue?
2. How does Indiana decide how much sand to put into the bag? What does he
appear to be doing? (What assumption is he making?)
3. What is the mass of the sand in the bag?
2.5 g/mL.)
(The density of sand is about
4. According to your calculations, is the bag of sand too light or too heavy?
5. If Indiana knew what you know about density, what volume of sand would he
have put into the bag?
Section 3: Density
1. What is the density of a block of marble with a mass of 594 g and a volume of
216 cm3?
2. Calculate the density of a material that has a mass of 52.457 g and a volume of
13.5 cm3?
3. A cubic sample of quartz has a density of 2.65 g/cm3 and the length of one side
of the cube is 4 cm. What is the mass of the quartz sample?
4. How many grams of tin would occupy 5.5 L if it has a density of
g/cm3?
7.265
5. The density of a sample of cork is 0.24 g/cm3. What is the volume of this sample
if it has a mass of 36 g?
6. The density of lead is 11.342 g/cm3. What would be the volume of a 200.0 g
sample of this metal?
Section 4: Density
1. A student finds a rock on the way to school. In the laboratory he determines that
the volume of the rock is 22.7 cm3, and the mass is 39.943 g. What is the
density of the rock?
2. If 30.943 g of a liquid occupy a space of 35.0 ml, what is the density of the liquid
in g/cm3?
3. What is the mass of a 350 cm3 sample of pure silicon with a density of 2.336
g/cm3?
4. The density of silver is 10.49 g/cm3. If a sample of pure silver has a volume of
12.993 cm3, what would the mass?
5. Pure gold has a density of 19.32 g/cm3. How large would a piece of gold be if it
had a mass of 318.97 g?
6. How many cm3 would a 55.932 g sample of copper occupy if it has a density of
8.92 g/cm3?
Section 5: Density
1. What is the density of a piece of wood that has a mass of 25.0 grams and a
volume of 29.4 cm3?
2. A piece of wood that measures 3.0 cm by 6.0 cm by 4.0 cm has a mass of 80.0
grams. What is the density of the wood? Would the piece of wood float in the
water?
3. A cup of gold colored metal beads was measured to have a mass of 425 grams.
By water displacement, the volume of the beads was calculated to be 48.0 cm3.
Given the following densities, identify the metal.
a. Gold 19.3 g/mL
b. Copper 8.85 g/mL
c. Bronze 9.87 g/mL
4. The volume of a solution was measured in a graduated cylinder (shown above).
If the mass of the solution is measured to be 60.75 grams, what is the density of
the solution?
5. An ice cube measuring 5.80 cm on each side has a density of 0.91 g/ml. What is
its mass?
6. 450 grams of gasoline is spilled. If the density is 0.665 g/mL, what volume of
gasoline is spilled?
7. The density of aluminum is 2.70 g/mL. If the mass of a piece of aluminum is 244
grams, what is the volume of the aluminum?
Section 6: Heat
1. What is heat?
2. What does the temperature of a sample measure?
3. What happens in a heat transfer?
4. Describe the three factors that affect the magnitude of the temperature change in
a heat transfer.
5. Given the following information, what would be the sign for q.
a. Energy is released to the surroundings
____ q
b. Energy is absorbed by the sample
____ q
Section 7: Specific Heat
1. Solve the following specific heat questions.
a. How much heat, in kilojoules, is required to raise the temperature of
320.0 g of water from 15.0 to 96.0°C?
b. How much heat, in kilojoules, is required to raise the temperature of
74.3 g of ethanol from -36.4 to 44.5°C?
c. A 638g block of lead initially at 27.0°C absorbs 2044J of heat.
What is the final temperature of the lead?
d. A 9.13g sample of vanadium is heated to 99.10°C and is then
dropped into 20.0g of water in a calorimeter. The water
temperature rises from 20.51 to 24.46°C. Calculate the specific
heat of vanadium.
Section 8: Specific Heat
Solve the following specific heat questions.
1. What is the specific heat of a substance that absorbs 2.5 x 103 joules of
heat when a sample of 1.0 x 104 g of the substance increases in
temperature from 10.0°C to 70.0°C?
2. What mass of water can be heated from 25.0° C to 50.0° C by the addition
of 2825 J?
3. What is the final temperature when 625 grams of water at 75.0° C loses
7.96 x 104 J?
4. A 1.0 kg sample of metal with a specific heat of 0.50 kJ/kg°C is heated to
100.0°C and then placed in a 50.0 g sample of water at 20.0°C. What is
the final temperature of the metal and the water?
5. A 2.8 kg sample of a metal is heated to 100.0°C then placed in a 50.0 g
sample of water at 30.0°C. What is the specific heat of the metal if the
final temperature of the metal and the water is 62°C?
Section 9: Specific Heat
1. When 12.29 g of finely divided brass (60% Cu, 40% Zn) at 95.0°C is
quickly stirred into 40.00 g of water at 22.0°C in a calorimeter, the water
temperature rises to 24.0°C. Find the specific heat of brass.
2. 175 grams of hot aluminum (100.°C, c=0.900 J/g·°C) is dropped into an
insulated cup that contains 40.0 mL of ice cold water (0.0°C, d= 1g/mL).
Determine the final temperature of the metal and the water.
3. A 15.75 gram piece of iron absorbs 1086.75 J of heat, and its temperature
changes from 25 °C to 175°C. Calculate the specific heat of iron.
4. What is the initial temperature of a 50.0 g piece of glass that cooled to
20.0 °C as it lost 5275 J of heat. The specific heat is 0.50 J/g°C.
5. A 10 gram hook with a specific heat of 0.40 J/g°C is heated within the
flame of a Bunsen burner. It is quickly dropped into 200 grams of water at
20 °C. The water temperature rises to 25 °C. What was the initial
temperature of the metal?
6. How much heat is required to raise the temperature of 10.0 grams of
aluminum from 22 °C to 55 °C if the specific heat of aluminum is
0.90 J/g°C?
Section 10: Phase Changes
The graph was drawn from data collected as a substance was heated at a
constant rate. Use the graph to answer the following questions.
At point A, the beginning of
observations, the substance
exists in a solid state. Material in
this phase has definite
___________ and
_____________. With each
passing minute, _____________
is added to the substance. This
causes the molecules of the
substance to vibrate
_____________, which we detect
by a ________________ rise in
the substance. We measure this
using a measuring device called
a _______________. At point B, the temperature of the substance is ______K
(do a conversion here). The solid begins to __________. At point C, the
substance is completely ____________ or in a ___________ state. Material in
this phase has a _______________ volume, but no _____________ shape. The
energy put to the substance between minutes 5 and 9 was used to convert the
substance from a ___________ to a ___________. This heat energy is called the
latent heat of ____________.
Between 9 and 13 minutes, the added energy increases the ______________ of
the substance. During the time from point D to point E, the liquid is
___________. By point E, the substance is completely in the __________ phase.
Material in this phase has no _____________ volume and no ___________
shape. The energy put to the substance between minutes 13 and 18 converted
the substance from a ___________ to a ___________ state. This heat energy is
called the latent heat of ______________. Beyond point E, the substance is still
in the ______________ phase, but the molecules are moving _______________
as indicated by the increasing ________________.
Which of these three substances was
likely used in this phase change
experiment?
Substance Melting point Boiling point
Bolognium
20 °C
100 °C
Unobtainium
40 °C
140 °C
Moxlium
70 °C
140 °C
Section 11: Phase Diagram
Refer to the phase diagram below when answering the questions below.
1)
What is the normal freezing point of this substance? ________
2)
What is the normal boiling point of this substance? ________
3)
What is the freezing point of this substance at 2.00 atm? ________
4)
If I had a quantity of this substance at a pressure of 1.25 atm and a
temperature of 3000 C and lowered the pressure to 0.25 atm, what phase
transition(s) would occur?
5)
At what temperature do the gas and liquid phases become
indistinguishable from each other?
6)
________
If I had a quantity of this substance at a pressure of 0.75 atm and a
temperature of -1000 C, what phase change(s) would occur if I increased
the temperature to 6000 C? At what temperature(s) would they occur?