- 1 -

Chemistry: Unit 6 Outline: States of Matter
Assignment
Podcast 6.1 (CB 1-5)
Worksheet A
Aluminum Can Crush
Podcast 6.2 (CB 7-11)
Demo: Boiling Water with Ice
Worksheet B
Podcast 6.3 (CB 13-17)
WB Page Number
Online
Pg 10-11
Pg 5
Online
In Class
Pg 12-14
Online
Lab : Heat Capacity of a Metal Pg 6-7
Pg 13-14
Online
Pg 15-17
Open Ended
Score Out of


100




100



100
Worksheet C
Podcast 6.4 (CB 19-21)
Worksheet D
Lab: Calculating ∆H rxn
of
Various Substances
Podcast 6.5 (CB 23-25)
Demo: Burning Paper with
Steam
Lab: Heat of Fusion of Ice
Online
In Class
Pg 8-9


100
Lab: Technology Lab
Worksheet E
Lab Test: Finding ∆H
Teacher Handout
Pg 18-22
Teacher Handout
100


Unit 6 Exam In Class 100
(You must score 85/100 on all assignments with a number to move to the next unit. For those assignments with a check, you need to do it to the satisfaction of your teacher)
- 2 -

Section 10.1: The Nature of Gases
1 Kinetic Molecular Theory (pg 267-272)
Define: Kinetic Energy
Summarize: The 3 tenants of the kinetic theory
Sketch: Figure 10.1
Complete the statements:

As you increase the temperature, the KE goes _____________

As you increase the temperature, the average velocity of the particles goes ________
Sketch: Figure 10.4 on page 272
3 Gas Pressure (pg 268-269)
Define: gas pressure, vacuum, atmospheric pressure, barometer
Fill in the following:
1.0
atm = ___________mmHg = ______________kPa
Sketch: Figure 10.2 on page 269
Section 10.2-10.3: The Nature of Liquids and Solids
5 KMT and Liquids (pg 274-275)
Sketch: Figure 10.5 on page 274 (just the molecules)
Define: Evaporation, vaporization, vapor pressure
Sketch: Figure 10.7 on page 275
Use: Figure 10.9 to answer the following question

The higher the temperature, the ____________ the vapor pressure.
7 Boiling Point and Vapor Pressure (pg 277-279)
Define: boiling point, normal boiling point
Sketch: Figure 10.11
Use This Section to Answer

The higher the altitude the ___________ the pressure

The higher the altitude the ___________the boiling point of a liquid

When the vapor pressure equals ___________________ the substance will boil
9 KMT and Solids (pg 280-283)
Define: melting point, allotropes, amorphous solids, glasses
Sketch Figure 10.13
Use this Section to Answer

Though a solid appears to not move, it is moving by ________________

Solids are solids because of _____________ bonds
Section 10.4: Changes of State
11 Phase Diagrams and Sublimation (pg 284-286)
Define: phase diagram, sublimation
Sketch: Figure 10.18 on page 284 (just the graph)
- 3 -

Section 11.1: Energy Transformations
13 Transformations-Exothermic-Endothermic (pg 293-295)
Define: Thermochemistry, Energy, Chemical Potential Energy, System, Surroundings, Law of
Conservation of Energy, Exothermic Endothermic
Sketch: Figure 11.3 on page 294
Explain: The difference between heat and temperature
15 Stoichiometry and Energy: Leave Blank for Teacher Notes
17 Heat Capacity and Specific Heat (pg 295-299)
Define: Calorie, Joule, Heat capacity, specific heat
Copy: Table 11.2 on page 296
Copy: Specific Heat Equation found on page 297
Section 11.2: Measuring & Expressing Heat Changes
19 Calorimetry (pg 300-303)
Define: Calorimetry, calorimeter, enthalpy (include it’s symbol)
Copy: Equation on page 301
Sketch: Figure 11.8 on page 300
21 Thermochemical Equations (pg 303-306)
Define: Thermochemical equation, heat of reaction, heat of combustion
Complete
 If a reaction is endothermic the value of ∆H goes on the ___________ side of the equation.
 If a reaction is exothermic the value of ∆H goes on the ___________ side of the equation.
Section 11.3: Heat in Changes of State
23 Heat of Fusion & Solidification (pg 307-309)
Define: molar heat of fusion, molar heat of solidification
Sketch: Figure 11.13 on page 307
25 Heat of Vaporization and Condensation, Solution (pg 310-313)
Define: Molar Heat of Vaporization, Molar heat of Condensation, Molar Heat of Solution.
Sketch: Figure 11.15 on page 310
- 4 -

Title: Aluminum Can Crush—Take Home Lab
Subject/Concept: Chemistry - Gas Laws
Purpose: The purpose of this activity is to observe the gas laws in action.
Materials: •1/8 cup water
• small pan of ice water
• 1 empty aluminum soda can
• 1 pair barbeque tongs
• 1 stove
Procedure:
1. Place 1/8 cup of water in an empty aluminum soda can.
2. Heat the can of water on the stove on medium until visible steam escapes from the can for a period of about 5-10 seconds.
3. With the barbeque tongs, grab the can and invert it into the pan of ice water.
Cautions:
1. Do not boil the can dry! It will melt onto the stove top!
2. Do not touch the aluminum cans with your hands while it is on the stove.
It is very hot.
3. Be careful not to spill or splash any of the boiling water in the can as you invert it.
Questions:
1. What gas replaces the air while the water is boiling?
2. What is the chemical formula for the gas in question #1?
3. Explain how each of the following contributes to the results:
a) the temperature of the gas cools when the can is removed from the heat
b) the gas inside the can condenses to form water droplets
4. What is the difference between an implosion and an explosion?
5. If cans are roughly 8” in circumference and 4.75” tall, how many pounds of pressure does the atmosphere place on the outside of the can? (1 atm = 14.7psi )
For Credit:
To receive credit, your parent or guardian must write a short note confirming that you performed the experiment for them and explained the results to their satisfaction using the concept of gas laws . Attach your note to the back of this sheet.
- 5 -

WPHS Chemistry
Identification of an Unknown Metal
In this lab we will be using lab techniques and basic chemical concepts to identify an unknown metal. Every metal has a unique set of properties. We will be using specific heat (also known as "heat capacity" or "specific heat capacity"). Your periodic tables have adequate listings for the purpose of this experiment, but several other sources also have listings of these values for pure materials: check the indices of the CRC Handbook, the Merck Index, or the Exploring the Elements books on the shelves around the room.
NOTES: Goggles are necessary, and long hair must be tied back . Record all data to the correct decimal place in your lab handbook. Since we are using digital thermometers, feel free to stir with the thermometer.
PROCEDURE - Specific Heat
To determine the specific heat of a metal sample, we will use a calorimeter, and the concept that in a closed system, heat lost by a hot object is gained by a cooler one. mC p
∆T (cold) = –mC p
∆T (hot)
To determine the initial (high) temperature of your metal sample, suspend it in a beaker of boiling water and keep it there until boiling has proceeded steadily for about two minutes. Record the temperature of the boiling water with a thermometer in a rubber stopper (it should not touch the beaker glass). This is the same as the initial metal temperature.
While the water/metal mixture is boiling, record the mass of the empty calorimeter cup.
Next, add just enough water to cover your piece of metal (estimate), and determine the combined mass. Keep track of the temperature of this water with a second thermometer.
Record the temperature of the cold water and of the metal just before combining them.
Immerse the metal sample in the cold water and record the final temperature of the mixture. It should change quickly at first, then level off, then cool back down slowly.
Record the level part.
NOTE: Perform one density trial then one specific heat trial, then repeat the whole thing two more times. Make sure Everything is dry for each trial.
- 6 -

Aluminum
Antimony
Carbon Steel
Cast Iron
Copper
Gold
Iron
Lead
Magnesium
Mercury
Molybedenum
Nickel
Silver
Tin
Titanium
Zinc
Data Table
Trial 1 Trial 2 Trial 3 initial temperature of metal __________ __________ __________ (C) temperature of cold water __________ __________ __________ (C) final temperature of mixture __________ __________ __________ (C) specific heat of water 4.18 4.18 4.18 (J/gC) mass of cold water (use Vol) __________ __________ __________ (g) change in water temperature __________ __________ __________ (C) change in metal temperature __________ __________ __________ (C) specific heat of metal __________ __________ __________ (J/gC)
Show a complete sample calculation for heat capacity and then determine which metal you have using the table below
Metal
0.46
0.13
1.05
0.14
0.25
0.54
0.23
0.21
0.54
0.39
Specific
Heat
(J/g ºC)
0.91
0.21
0.49
0.46
0.39
0.13
- 7 -

Heat of Fusion of Ice Name
INTRODUCTION:
The amount of energy required to convert a solid to a liquid, at constant pressure and temperature, is called the heat of fusion of the substance. In this experiment, the heat of fusion of ice will be determined.
The ice will be melted by placing it in a known volume of hot water contained in a plastic cup. The system will be left undisturbed until all the ice has melted. The amount of heat lost by the hot water in this process can be calculated according to the following equation.
Procedure
1.
Get 100.0 mL of water at the highest temperature you can out of the tap.
2.
Place the water in a Styrofoam cup.
3.
Measure the temperature of the water.
4.
Simultaneously, the other partner should be getting a handful of ice cubes that need to be dried.
5.
Place the ice cubes in the cup of hot water and wait until the ice cubes have completely melted.
6.
Measure the final temperature.
7.
Measure the total volume of the cool water.
8.
Place all data in the table below.
9.
For the masses: Assume that the density of water is 1.0 g/mL.
Data
DATA TABLE:
Initial mass of hot water.
Initial temperature of hot water.
Final temperature of water and melted ice.
Final mass of water and melted ice. mL
ºC
ºC
Change in Temp of Hot Water
Change in Temp of Ice mass of ice added mL
ºC
ºC mL
- 8 -

Calculations
1.
Calculate the change in temperature of the hot water. This is simply the initial temperature of hot water - final temperature of water and melted ice.
2.
Calculate the mass of the hot water. Don’t forget that 1 ml of water has a mass of 1 g . This is because the density of water is 1 g / ml
. So the volume in ml is the mass in grams.
3.
Calculate the heat lost by the hot water. (See equation 1 in the introduction.) The specific heat of water is
4 .
18 g
J

C
.
Your answer will have Joule as the unit.
4.
Calculate the volume of ice melted. (See equation 2 in the introduction.)
5.
Calculate the mass of ice melted. (See equation 3 in the introduction.) As in step 8, 1 ml of water has a mass of 1 g
. So it’s just the volume changed to grams.
6.
Calculate the heat of fusion of ice in joules / g
.
Questions
1.
The accepted value for the heat of fusion of water (ice) is 334 joules / g
. What is your percentage of error?
2.
What is the most important source of error?
3.
What happened to the temperature of the ice as it was melting?
- 9 -

Worksheet A: KMT and Pressure Name _____________________
1.
Use kinetic theory to explain what causes gas pressure.
2.
Convert the following Pressures: a.
600 mm Hg into atm b.
190 kPa into atm c.
2.3 atm into mm Hg d.
1.5 atm into kPa
3.
What is the equation that relates kinetic energy to Kelvin Temperature
4.
What is the temperature at absolute zero
5.
Use kinetic theory to explain the difference between evaporation and boiling of a liquid.
- 10 -

6.
Use the chart to answer the following questions. a.
What is the vapor pressure of ether at 40ºC? b.
What is normal boiling point of water? c.
What is the normal boiling point of benzene?
7.
How is the average kinetic energy of water molecules affected when you pour hot water from a kettle into cups at the same temperature as the water?
- 11 -

Worksheet B Name __________________
1.
What is the relationship between atmospheric pressure and altitude? What effect does this have on the boiling point of water?
2.
Define vapor pressure.
3.
What is the full definition of the boiling point of a liquid?
4.
Explain why the boiling point of a liquid varies with atmospheric pressure.
5.
Using the diagram above: What would happen to the CO2 if you: a.
Heat it up from -60º to 30º C at 6.0 atm? b.
Increase the pressure from 2.0 atm to 60 atm at a temperature of 0ºC? c.
Decrease the pressure from 80.0 atm to 1 atm at a temperature of 25ºC? d.
Increase the temperature from -80ºC to +80ºC at a pressure of 1.0 atm? e.
Increase the temperature from -60ºC to 20ºC at a pressure of 70 atm?
- 12 -

WS C: Energy Transformations & Heat Capacity Name ________________
1.
Which has more heat: Rampart Reservoir or a cup of boiling water? Explain your answer.
2.
What always happens when two object of different temperatures come into contact? Give an example from your daily life.
3.
Classify these process as exothermic or endothermic:

Condensing steam

Evaporating alcohol

Burning alcohol

Baking a potato
4.
Energy always flows from _______ to _____________.
5.
When you open your door in the winter and your mom says: “Quit letting the cold in the house,” what should you politely tell her?
- 13 -

Substance
Water
Heat
Capacity
(J/gºC)
4.18
Substance Heat
Capacity
(J/gºC)
Grain
Alcohol
2.4
Steam 1.7 Ice
Glass
Silver
Lithium
2.1
Chloroform 0.96
0.50
0.24
0.14
Aluminum 0.90
Iron 0.46
Mercury
Copper
0.14
0.39
Uranium 0.12 Gold
Use the table above to answer the following questions
0.13
6.
A 75.0g sample of a metal at 98.0º C is dropped into a container of 350. g of water at 24.0ºC, The final temperature is 24.5 ºC. What is the specific heat of the metal?
7.
A 55.0 g sample of a metal at 90.0º C is dropped into a container of 250 g of water at 22.0ºC, The final temperature is 23.4 ºC. What is the metal?
8.
A 200.0 g sample of a metal at 92.0º C is dropped into a container of 100 g of water at 26.0ºC, The final temperature is 45.6 ºC. What is the metal? What is the percentage error?
9.
A 45.2 g sample of Silver at 101.0 ºC is dropped into 300.0 g of water at 30.6 ºC.
What is the final temperature of the water?
- 14 -

WS D: Energy Stoichiometry & Calorimetry Name __________________
1.
Nitrogen reacts with hydrogen according to the following equation.
N
2
+ H
2
 NH
3
+ 231 kJ
How much energy will be released when 13.0-g of nitrogen reacts?
How much energy will be released when 2.5L of hydrogen reacts?
2.
Carbon disulfide is an important industrial solvent. It is prepared by the reaction of coke with sulfur dioxide:
5C(s)+2SO
2
(g)

CS
2
(s) +4CO(g) ∆H = 23.5-kJ
How much energy will be required when 32.4-g of Carbon disulfide is produced?
How much energy will be required to react 21.1-L of sulfur dioxide?
3.
Silver nitrate reacts with calcium to make calcium nitrate and silver. The reaction is exothermic and produces 18.7 kJ/mol of energy.
AgNO
3
+ Ca

Ca(NO
3
)
2
+ Ag
How much energy will be produced when 12.3-g of silver nitrate react?
How many grams of silver nitrate reacted if 13.7 kJ of energy is released?
- 15 -

4.
Magnesium reacts with hydrochloric acid in a single replacement reaction. The value of ∆H =-221 kJ/mol. (You will need to write the balanced chemical equation.
How many grams of magnesium will be made if 365-kJ is released?
How much energy will be released if 9.45-g of magnesium reacts?
5.
Ammonium sulfate reacts with barium hydroxide endothermically. ∆H = + 127 kJ/mol. (You will need to write the balanced chemical equation.)
How much energy will be required to react completely 34.5-g of barium hydroxide?
If 395-kJ of energy is absorbed, how many grams of ppt will be formed?
6.
When 12.3-g of magnesium reacts with 1000.0g of hydrochloric acid it raises the temperature from 22.5˚C to 48.3˚C. What is the value of ∆H?
7.
When 13.5-g of ammonium nitrate is dissolved in water it cools 1000.0-g of water from 32.3˚C to 29.5˚C. What is the value of ∆H?
- 16 -

Calculate the value of ∆H given the following data for a bomb calorimeter:
Temperature initial: 22.5˚C
Temperature final: 33.6˚C
Mass of water heated: 125.0-g
Mass of benzene, C
6
H
6
: 1.05g
8.
The combustion of 25.6-g of propane, C
3
H
8
raises the temperature of 1000-g of water by 16.8˚C. What is the value of ∆H?
9.
The single replacement reaction:
Li + Al
2
(SO
4
)
3

Li
2
SO
4
+ Al has a ∆H of –229.7 kJ/mol. If 12.1-g of Li reacts, how much will the temperature of
1000.0-g of water rise? (Hint: balance the reaction and then use Q=mc∆T and solve for ∆T)
10.
For the dissolving of sulfuric acid, H
2
SO
4
the value of ∆H=-236 kJ/mol. If 2.54-g of sulfuric acid dissolves in 100.0-g of 20.0˚C water, what will be the final temperature of the water?
- 17 -

A
WS E: Phase Change Problems Worksheet Name____________________
C
1.
In the diagram above, label all of the states of matter.
2.
Assuming the above diagram is water, label the temperatures of the flat portions of the diagram above.
3.
In the first rising portion of the graph (a), describe what is happening as energy is added. Discuss this in terms of the kinetic molecular theory.
4.
In the 1 st
flat portion of the graph (b), describe what is happening as energy is added. Discuss this in terms of bonding forces of attraction.
5.
In the 2 nd
rising portion of the graph (c), describe what is happening as energy is added. Discuss this in terms of the kinetic molecular theory.
6.
In the 2 nd
flat portion of the graph (d), describe what is happening as energy is added. Discuss this in terms of bonding forces of attraction.
7.
In the 3 rd
rising portion of the graph (e), describe what is happening as energy is added. Discuss this in terms of the kinetic molecular theory
- 18 -

Substance
H2O
Grain
Alcohol
Benzene m.p.
(ºC)
0.00
-98
5.0
∆H
(kJ/g)
0.333 fus
0.0987
0.1265
64
80 b.p.
ºC
100.00
∆H
2.26
1.10
0.394 vap
(kJ/g)
Specific Heat –C-
(J/g ºC)
Ice: 2.09
Water: 4.18
Steam: 1.7
Solid: 1.2
Liquid: 2.4
Gas: 1.9
Solid: 0.55
Liquid: 0.96
Gas: 1.09
8.
What is the formula used for calculating the heat involved in a phase change?
9.
During a phase change, how much does the temperature change? How much does the KE change? Does the potential energy change?
10.
What is the formula used to calculate the heat required to warm or cool one phase of matter?
11.
When you heat one phase of matter, how do you know that the KE changes?
12.
What is meant by the negative sign in an answer like "-46.8 kJ"? When would you use a positive sign?
- 19 -

13.
If you must add 25 kJ to raise the temperature of an ice cube from -15°C to -10°C, is this an endothermic or an exothermic process.
14.
How much heat is required to raise 40 grams of water from 30°C to 70°C?
15.
How much water can be raised from 25°C (room temperature) to 37°C body temperature by adding the 2,000 kJ in a Snickers Bar?
16.
Which releases more heat when it is lowered by 8°C, 100 grams of ice, water, or steam? How much heat is released by the one which releases the most?
17.
How much heat does it take to melt 65 grams of ice at 0°C?
- 20 -

18.
Calculate the amount of energy required to change 100 grams of solid ice at 0°C to gaseous steam at 100°C. (Be aware of units: kJ or J?) How many steps does this take?
19.
Calculate the amount of energy released by cooling 59 grams of liquid water from
+25°C to ice at -25°C. (Be aware of units: kJ or J?) How many steps does this take?
20.
How much heat would it take to raise 5 grams of H
2
O from -50°C to +200°C?
How many steps does this take?
21.
How much heat is needed to melt a tray of 14 ice cubes, presently at 0˚ C, each having a mass of 35 g.
- 21 -

22.
How much energy is required to bring 45 g of benzene from - 10˚C to 70˚C?
23.
How much energy is required to bring 1 kg of grain alcohol in the liquid state from its freezing point to 10˚ above its boiling point?
24.
What will be the temperature of water if if 2000 J or energy is added to 100 g of ice at 0˚C? Will all of it melt? If not how much has melted and how much remains?
25.
What will be the temperature of grain alcohol if 10,000 J of energy is added to
400 g of grain alcohol at -50˚C?
26.
What will be the temperature of benzene if 30,000 J of energy is added to 1 kg of benzene at -5˚C?
- 22 -

A
WS E: Phase Change Problems Worksheet
Name____________________
1.
In the diagram above, label all of the states of matter.
2.
Assuming the above diagram is water, label the temperatures of the flat portions of the diagram above.
3.
In the first rising portion of the graph (a), describe what is happening as energy is added. Discuss this in terms of the kinetic molecular theory.
4.
In the 1 st
flat portion of the graph (b), describe what is happening as energy is added. Discuss this in terms of bonding forces of attraction.
5.
In the 2 nd
rising portion of the graph (c), describe what is happening as energy is added. Discuss this in terms of the kinetic molecular theory.
6.
In the 2 nd flat portion of the graph (d), describe what is happening as energy is added. Discuss this in terms of bonding forces of attraction.
7.
In the 3 rd
rising portion of the graph (e), describe what is happening as energy is added. Discuss this in terms of the kinetic molecular theory
- 23 -

Substance
H2O
Grain
Alcohol
Benzene m.p.
(ºC)
0.00
-98
5.0
∆H
(kJ/g)
0.333 fus
0.0987
0.1265
64
80 b.p.
ºC
100.00
∆H
2.26
1.10
0.394 vap
(kJ/g)
Specific Heat –C-
(J/g ºC)
Ice: 2.09
Water: 4.18
Steam: 1.7
Solid: 1.2
Liquid: 2.4
Gas: 1.9
Solid: 0.55
Liquid: 0.96
Gas: 1.09
8.
What is the formula used for calculating the heat involved in a phase change?
Q=∆Hm
9.
During a phase change, how much does the temperature change? How much does the KE change? Does the potential energy change?
None: None: PE changes
10.
What is the formula used to calculate the heat required to warm or cool one phase of matter?
Q=mc∆T
11.
When you heat one phase of matter, how do you know that the KE changes?
Because the Temperature changes
12.
What is meant by the negative sign in an answer like "-46.8 kJ"? When would you use a positive sign?
Energy is released
- 24 -

13.
If you must add 25 kJ to raise the temperature of an ice cube from -15°C to -10°C, is this an endothermic or an exothermic process.
Endothermic: You are adding the energy
14.
How much heat is required to raise 40 grams of water from 30°C to 70°C?
Q
 mc

T

( 40 g )( 4 .
18 g
J

C
)( 40

C )

6688 J

6 .
7 kJ
15.
How much water can be raised from 25°C (room temperature) to 37°C body temperature by adding the 2,000 kJ in a Snickers Bar?
Q
 mc

T
2000
2 , 000 kJ
,

2 , 000 , 000 J
000 J
 m ( 4 .
18 g
J

C
)( 12

C ) m

39872 g

39 .
8 kg
16.
Which releases more heat when it is lowered by 8°C, 100 grams of ice, water, or steam? How much heat is released by the one which releases the most?
Water will release the most energy since the specific heat of liquid water is the highest
Q
 mc

T
( 100 g )( 4 .
18 g
J

C
)( 8

C )

3344 J

3 .
3 kJ
17.
How much heat does it take to melt 65 grams of ice at 0°C?
Q
 
H fus m

( 0 .
333 kJ g
)( 65 g )

21 .
6 kJ
18.
Calculate the amount of energy required to change 100 grams of solid ice at 0°C to gaseous steam at 100°C. (Be aware of units: kJ or J?) How many steps does this take?
0

( s )

0

( l )
: Q
 
H fus m

( 0 .
333 kJ g
)( 100 g )

33 .
3 kJ
0

( l )
100


100

( l )
: Q
( l )

100

( g )
:

Q mc


T

( 100 g )( 4 .
18 g
J

C
)( 100

C )

H vap m

( 2 .
26 g
J

C
)( 100 g )


41800 J
226 kJ
226 kJ

41 .
8 kJ

33 .
3 kJ

301 .
1 kJ

41 .
8 kJ
- 25 -

19.
Calculate the amount of energy released by cooling 59 grams of liquid water from
+25°C to ice at -25°C. (Be aware of units: kJ or J?) How many steps does this take?
25

( l )

0

( l )
: Q
 mc

T

( 59 g )( 4 .
18 g
J

C
)( 25

C )

6166 J

6 .
2 kJ
0

( l )

0

( s )
: Q
 
H fus m

( 0 .
333 g
J

C
)( 59 g )

19 .
6 kJ
0

( s )
 
25

C
( s )
: Q
 mc

T

( 59 g )( 2 .
09 g
J

C
)( 25

C )

3082 J

3 .
1 kJ
6 .
2 kJ

19 .
6 kJ

3 .
1 kJ

28 .
9 kJ
20.
How much heat would it take to raise 5 grams of H
2
O from -50°C to +200°C?
How many steps does this take?

50

( s )
0

( s )


0

( l )
0

( l )
: Q
: Q
 
 mc

T
H fus m

( 5 g )(

( 0 .
333
2 .
09 kJ g
)( 5 g
J

C
)( 50

C ) g )

1 .
67 kJ

522 J

0 .
52 kJ
0

( l )
100


( l )
100

(
 l )
100

: Q
( g )

: Q mc


T

H
 vap
( 5 g )( 4 .
18 m

( 2 .
26 g
J

C
)( 100

C ) g
J

C
)( 5 g )

2090

11 .
3 kJ
J
100

( g
0 .
52 kJ
)

200

( g )

1 .
67 kJ
: Q
 mc

2 .
09 kJ

T

( 5 g

11 .
3 kJ

)( 1 .
7
0 .
85 g
J

C
)( 100

C ) kJ

16 .
43 kJ

850 J

2 .
09 kJ

0 .
85 kJ
21.
How much heat is needed to melt a tray of 14 ice cubes, presently at 0˚ C, each having a mass of 35 g.
35 g 14 iceCube x iceCube
Q
 
H fus m

(
1
0 .
333

490 gIce kJ g
)( 490 g )

163 kJ
22.
How much energy is required to bring 45 g of benzene from - 10˚C to 70˚C?

10

( s )
5

( s )


5

5

(
( l ) s )
: Q
: Q

 
H mc

T fus m


( 0
( 45 g
.
)(
1265
0 .
g
J

C
55
)( g
J

C
)( 15

C )
45 g )


5 .
69 kJ
371 J

0 .
37 kJ
5

( l )

70

C
( l )
: Q
 mc

0 .
37 kJ

5 .
69 kJ

2 .
81 kJ
T

( 45 g

8 .
87 kJ
)( 0 .
96 g
J

C
)( 65

C )

2808 J

2 .
81 kJ
- 26 -

23.
How much energy is required to bring 1 kg of grain alcohol in the liquid state from its freezing point to 10˚ above its boiling point?

98

( l )

64

( l )
: Q
 mc

T

( 1000 g )( 2 .
4 g
J

C
)( 162

C )

388800 J

389 kJ
64

( l )
64

( g )

64

( g )

74

C
: Q
( g )
 
H vap m

( 1 .
10 g
J

C
)( 1000 g )

1100 kJ
: Q
 mc

T

( 1000 g )( 1 .
90 g
J

C
)( 10

C )

19 , 000 J
389 kJ

1100 kJ

19 .
0

1508 kJ

19 .
0 kJ
24.
What will be the temperature of water if 2000 J or energy is added to 100 g of ice at 0˚C? Will all of it melt? If not how much has melted and how much remains?
0

( s )

0

( l )
:
 
fus

( 0 .
333 kJ g
)( 100
)

33 .
3

2
 
fus
2

( 0 .
333 kJ g
)
6 .
0
6 %
..
..
...
0

..
..
'
..
..
25.
What will be the temperature of grain alcohol if 10,000 J of energy is added to
400 g of grain alcohol at -50˚C?

50

( s )
Q


64

( l ) mc

T
: Q
 mc

T

( 400 g )( 2 .
4 g
J

C
)( 114

C )

109440 J

10 , 000 J
10

T
, 000 J

( 400 g )( 2 .
4 g
J

C
)(

T )

10 .
4

C

50

C

10

C
 
40

C
26.
What will be the temperature of benzene if 30,000 J of energy is added to 1 kg of benzene at -5˚C?

5

( s )

5

( s )
: Q
 mc

T

( 1000 g )( 0 .
55 g
J

C
)( 10

C )

5500 J
StillMoreE nergyLeft
Q
 
H fus m

( 0 .
1265 kJ g
)( 1000 g )

126 .
5 kJ

126500 J
Since : It : Won ' t : All : Melt

5

:: Then : It : will : be : at : it ' s : freezing : po int
- 27 -