Name: ____________________________________________
Unit 3B&C Study Guide
Petroleum: An Energy and Building-Material Source
Why are hydrocarbons commonly used as fuels?
Why are carbon-based molecules versatile as chemical building blocks?
1
Date: ___________
Right Now
Quick Notes: Energy vs Temperature
Energy
Temperature
Definition
Units
Examples
What
happens
when you
have a lot
of:
How you
measure:
2
Energy Conversions in a Car
Date: ______________
In one sense, an automobile – whether powered by electricity, gasoline, or solar energy can be considered a collection
of energy-converting devices. The principle behind a car’s engine is an internal combustion engine—a tiny amount of
fuel is put in a small, enclosed space and ignited. This releases energy which allows a piston to move. Currently, gasoline
is the preferred fuel for the average car. However, gasoline-powered cars are very inefficient. Only about 18% of crude
oil becomes gasoline. The combustion of gasoline produces carbon dioxide and water along with pollutants such as
carbon monoxide, nitrogen oxides, and unburned hydrocarbons.
1. How does car movement obey the Law of Conservation of Energy?
2. Name the type of energy (kinetic energy, potential energy, or heat) involved in each step required to move a car.
3. According to the diagram to the
right how much energy is “lost”?
4. Energy is always conserved. How
is it possible that energy is “lost”?
5. What really happens to the “lost” energy from gasoline?
6. People have tried to increase the efficiency of the internal combustion energy, but they are never able to obtain
100 % efficiency. Hypothesize why it is impossible to obtain technology that achieves full efficiency.
3
Energy Vocab
Date: ______________
Skim through sections 3B&C to find the major vocabulary words. For each word, write the definition. Then use the book
to come up with an example or a statement that correctly identifies the word: context from the text that will help you
remember what the word means. The memory hook can be a picture, an example, or a page number.
Word
Definition in your own words
Potential energy
Kinetic energy
Endothermic
Exothermic
Law of Conservation
Energy
Specific Heat
Capacity
Heat of Combustion
Functional Group
4
Memory Hook
Heat Transfer
Date:________________
Not all materials respond the same when they absorb heat energy. Some materials need a lot of energy to make the
temperature rise, while others don’t need as much. You will practice heat calculations to determine the relationships
that exist with heat.
Background Information:
1. What is heat?
2. What is the equation that calculates the amount of heat?
3. In what direction is heat always transferred?
4. What does a negative heat mean? When will this happen?
5. What does a positive heat mean? When will this happen?
Example: Calculating Heat transfer for Ice in Water
6. What are the variables that you need to calculate the heat transferred?
a. The specific heat of water in joules?
b. What is the mass of the water used (Hint: the density of water is 1 g/mL)?
c. How much did the temperature of the water change?
7. Calculate the heat transferred (in Joules) for water. Show your work.
5
Relationship between Heat and Specific Heat
1. Run ScienceLab/ChemSimulation/Heat_Metal_Ice.html
2. Follow the procedure below for Silver, Gold, Copper, and Iron
a. Click on a metal
b. Change the starting temperature of the metal to 220 ˚C.
c. Click on start.
d. Record the variables needed to calculate the amount of heat transferred.
e. Calculate the heat transferred – show your work!
f. Click Reset
Silver
Gold
Copper
Iron
Specific Heat of
the Metal (J/g ˚C)
Specific Heat of
Water (J/g ˚C)
Mass of Water
Used (g)
Change of
Temperature of
the water (˚C)
Heat is
transferred from:
Heat is
transferred to:
Calculate the
Heat Transferred
for the water (J)
Heat Transferred
for the solid?
3. What is the relationship between the specific heat of the metal and the amount of heat transferred?
(Direct or Indirect?!?!)
4. Water has a very large specific heat. Is it easy to hard to change the temperature of a body of water?
6
Identifying Metal from Specific Heat
SHOW YOUR WORK FOR ALL CALCULATIONS!
Date: _________________
1. What was the final temperature of the metal?
a. Trial 1
b. Trial 2
2. What was the ΔT for the metal?
a. Trial 1
b. Trial 2
3. What was the ΔT for the water?
a. Trial 1
b. Trial 2
4. Calculate the heat change for the water. (Specific heat capacity (C) for water is 4.184 J/goC.)
a. Trial 1
b. Trial 2
5. Calculate the heat change for the metal. (Remember heat can never be created or destroyed)
a. Trial 1
b. Trial 2
6. Calculate the specific heat of the metal.
a. Trial 1
b. Trial 2
7. Use the data table to identify the metal used in the experiment. 
7
Describing Energy Notes
Date: __________________
Energy is the ability to cause change. In chemistry we deal with two main forms of energy: Kinetic Energy (the energy of
movement) and Potential Energy (the stored energy). Thermal Energy is the combination of kinetic and potential
energy. We can describe energy by two terms: Exothermic and Endothermic. These terms are opposites of each other.
Exothermic
Endothermic
What do the prefixes
mean?
What happens to energy of
the reaction?
What happens to energy of
the surroundings?
What happens to
temperature of the
surrounding?
Compare the potential
energy of the reactants and
the products.
What does the energy
graph look like?
What is the general
chemical equation?
Classify the following events as exothermic (exo) or endothermic (endo).
1. Releases heat: __________
7. Cooking an egg: __________
2. Absorbs heat: __________
8. Burning a match: __________
3. Heat is found with the reactants: __________
9. Formation of clouds: __________
4. Heat is found with the products: __________
10. Evaporating water: __________
5. Bouncing a ball: __________
11. Photosynthesis: __________
6. Making ice cubes: __________
12. Cellular Respiration: __________
8
Date: ___________
Right Now
Quick Notes:
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9
3B7 Supplement: Using Heats of Combustion
Date: ______________
With enough oxygen gas present in a reaction, complete combustion occurs. Complete combustion can be described by
the chemical equation: hydrocarbon and oxygen gas react forming carbon dioxide, water, and heat. Because
combustion is a highly exothermic reaction, heat—thermal energy—is written as a product. A reaction is complete
when the correct quantity of heat—thermal energy—is included. The total thermal energy is the quantity of
hydrocarbon burned multiplied by the heat of combustion. Heats of combustion can either be given in terms of KJ/mole
or KJ/g. In a balanced reaction you know the number of moles, therefore you need to use KJ/mole. When you know the
mass burned you use KJ/g.
1. Coal is simply carbon. Carbon has a Heat of Combustion of 32.8 KJ/g and a Molar Heat of Combustion of 394 KJ/mol.
a. Write a balanced chemical equation for the combustion of coal.
b. How much energy is released in the complete combustion of carbon?
c. An average grill uses 720 g of carbon. For the complete combustion of a grill filled with carbon, how much
energy is released?
2. Ethane is the second-largest component of natural gas. Ethane’s Heat of Combustion is 52.0 KJ/g and a Molar Heat
of Combustion is 1560 KJ/mole.
a. Write a balanced chemical equation for the combustion of ethane.
b. How much energy is released in the complete combustion of ethane?
c. If you were to burn 5 grams of ethane, how much of energy is released?
3. The major component in gasoline is octane. Octane has a Heat of Combustion of 47.8 KJ/g and a Molar Heat of
Combustion of 5,450 KJ/mole.
a. Write a balanced chemical equation for the combustion of gasoline. (Hint: the coefficient for octane is 2.)
b. How much energy is released in the complete combustion of octane?
c. A gallon of gasoline contains 2660 g of octane. For the complete combustion of 1 gallon of gasoline, how
much energy is released?
4. Based on the heats of combustion for carbon, ethanol and octane that you used in this activity, what is the
relationship between the number of carbon atoms and the Heat of Combustion? (Direct or Indirect?!?!)
5. Gram for gram, which is the better fuel – carbon or octane? Explain.
10
Extra Credit: Calculating the amount of gasoline
Date: __________________
Complete the questions on a SEPARATE page and turn in no later than the day of the 3B/C test. Show ALL WORK for
ANY credit. Each correct answer will give you 0.5 points EC.
Example: Let’s assume your family drives 200 miles each week and that the car can travel 25 miles on one gallon of
gasoline. How much gasoline does the car use in one year? And how much does that cost?
Some conversions needed: 200 miles
25 miles
52 weeks
1 week
1 gallon
1 year
200 miles x 1 gallon x 52 weeks = 416 gallons in a year
1 week
25 miles 1 year
And if gasoline costs $3 per gallon: 416 x $3 = $ 1,248
1. In one year in a car that averages 23.0 miles per gallon and travels 11,000 miles annually:
a. How much fuel will be burned in a year?
b. How much does the yearly amount of fuel cost?
c. How many gallons of gasoline are wasted if cars only use 25% of energy released by burning gas?
d. How much money is lost due to inefficiency?
2. In one year in a hybrid-powered car that averages 50.0 miles per gallon and travels 11,000 miles annually:
a. How much fuel will be burned in a year?
b. How much does the yearly amount of fuel cost?
c. How many gallons of gasoline are wasted if cars only use 25% of energy released by burning gas?
d. How much money is lost due to inefficiency?
3. Suppose a new car averages 70 miles per gallon and has an engine with 40% efficiency. How much fuel would be
saved annually?
11
3B9 Reading Guide: Altering Fuels
Date: ________________
As you read the section, complete the chart below by describing some ways that fuels are altered for gasoline engines.
Use your own words.
 Why must fuels be altered?
Process
Description
Cracking
Alteration of octane rating
Oxygenated fuels
12
Examples
Date: ___________
Right Now
Quick Notes:
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13
3C4-6 Reading Guide: Functional Groups
Date: ________________
A functional group is a cluster of atoms that is found in various molecules. The group gives the molecule its characteristic
properties. Several groups may occur in one molecule which would give the molecule a mixture of properties.
Note: R stands for the rest of the molecule, other than the functional group, and signifies a group of atoms including at
least one carbon atom bonded to the functional group.
Name
Alkene
General
Formula
Suffix of Name
Major Use
Example
CxH2x
-ene
Manufacturing
plastics
Propene
Alkyne
Alcohol
Ester
Carboxylic Acid
14
Date: ___________
Right Now
Quick Notes:
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15
The Builder Molecules
1. What elements are present in an organic compound?
Date:___________
2. What happens between atoms in a covalent bond? Why do elements form covalent bonds?
3. How many covalent bonds do the following elements make?
a. Carbon: _______
b. Hydrogen: _______
c. Oxygen: _______
4. Compare the covalent bonds by filling out the table below
Number of
How is it
Relative length of
Type of bond
Electron Pairs
represented?
bond
Shared
Relative amount
of movement in
atoms
Relative
Strength of
bond
Single covalent
Double Covalent
Triple Covalent
5. Use the models to find the unique features of functional groups.
Type of
Example 1 Name
Example 2 Name
Molecule
& Structural Formula
& Structural Formula
Alkene
Alkyne
Alcohol
Ester
Carboxylic
Acid
16
What three things do the
examples have in common?
3C6 Supplement: Builder Molecules
Date: ____________
Compounds are classified according to the functional group that is present in their molecular structure. Find and circle
the functional group in each molecule, and identify it as a carboxylic acid, alcohol, ester, alkane, or none of the above.
11. Which structural formula(s) from above could have an isomer and still contain the same functional group?
12. Draw the isomers for the structural formulas identified in #11.
17
Date: ___________
Right Now
Quick Notes:
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18
Polymer Structure and Property
Date: ___________
Polymers are long molecules that contain a chain of repeating units. When a polymer is unmodified, the
arrangement of covalent bonds in long, string like polymer molecules causes the molecules to coil loosely. In this form,
the polymer is flexible and soft. We use polymers in many everyday products, such as bottles, Styrofoam, synthetic
clothing and plastic bags.
We can change the properties of a polymer by adding molecules that act as internal lubricants among the polymer
chains. One way to change a polymer’s properties is to form polymer chains perpendicular to the main chain, forming
side chains. These polymers are called branched polymers. The extent of branching can be controlled by adjusting
reaction conditions. Figures (a) and (b) in the diagram are branched.
Another way to alter the properties of polymers is through cross-linking which
connects two straight chains. Polymer rigidity can be increased if the polymer chains
are cross-linked so that they can no longer move or slide readily. You can see this for
yourself if you compare the flexibility of a plastic soda bottle with that of its screw-on
cap. Polymer cross-linking is much greater in the cap. Figures (c) and (d) in the diagram
are cross-linked.
1. What is a polymer? What are some uses of polymers?
2. What’s the difference between branched-chain and cross-linked polymers?
3. If a pencil line represents a linear polymer, draw a collection of loosely coiled polymer molecules.
4. Draw at least two different models of branched-chain polymers.
5. Draw several linear polymer chains that have been cross-linked.
6. How do branching and cross-linking change the properties of a polymer?
19
Date: ___________
Right Now
Quick Notes:
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20
3C1&7 Reading Guide: Petrochemicals and Condensation Polymers
Date: ___________
Compare addition polymers and condensation polymers in the chart below. Include structural formulas and reactions
that produce these polymers.
Addition Polymers
Condensation Polymers
Structural Formula:
Structural Formula:
Reaction that produces these polymers:
Reaction that produces these polymers:
Other information:
Other information:
Similarities
21
3B&C Review
1. Classify each of the following as an example of kinetic energy or potential energy:
a. a basketball resting on the ground
__________________________
b. a skier moving down a slope
__________________________
c. a spinning fan
__________________________
d. a candle prior to being burned
__________________________
2. Explain the law of conservation of energy.
3. What is the difference between potential energy and kinetic energy?
4. Energy is not always completely converted from potential energy to a useable form of energy. Typically, what form
does “lost energy” take?
5. What is the general equation for the complete combustion of a hydrocarbon?
6. Consider the reaction: CO + H2 + O2 → CO2 + H2O + 525 kJ.
a. Is energy released or absorbed?
b. Classify this reaction as exothermic or endothermic.
c. Draw a temperature vs. time graph for the reaction. d. Draw a potential energy vs. time graph for the reaction.
7. In a laboratory activity, a student team measures the heat released by burning an unknown fuel source. Remember
that the specific heat of water (C) is 4.18 J/g*oC.
Mass of water:
188.5 g
a. Calculate the amount of heat that the water absorbs.
Initial water temperature: 9.2 C
Final water temperature:
51.9 C
Mass of fuel burned:
0.725 g
b. How much heat does the fuel release?
c. What assumption do you make to answer part “b” above? What are weaknesses of that assumption?
22
8. Why is burning a candle an exothermic process even though we have to provide energy for it to start?
9. What are organic molecules?
10. You are familiar with petroleum’s use as an energy source. It is also used for “building.” What does this mean?
11. Polymers can be chemically altered to exhibit physical properties that are useful for a specific purpose. Cross-linking
is one way that chemists alter the properties of a given polymer. What is cross-linking?
12. Compare a molecule containing four carbon atoms that represents an alcohol, a carboxylic acid, and an ester
a. alcohol
b. carboxylic acid
c. ester
Formula:
Formula:
Formula:
Name:
Name:
Name:
Structural Formula:
Structural Formula:
Structural Formula:
13. Does each of the following pairs represent isomers or the same substance? Explain.
Structural Formula 1 Structural Formula 2 Isomer or Same?
Type of Compound
CH2=CH−CH2−CH3
CH3−CH2−CH=CH2
14. Draw picture of a polymer with and without cross-links.
23
24
*Explain endothermic and
exothermic reactions in terms of
total energy involved in bond
breaking and bond making
5.
7. Identify the functional groups in
alcohols, ethers, esters and
carboxylic acids by looking at
structural formulas.
6. *Calculate heat transfer in a
combustion reaction by
analyzing lab data.
*Identify energy of reactants,
activated complex, and products
on potential energy diagrams.
*Define the law of conservation
of energy and give examples from
lab that support the law
3.
4.
*Differentiate between kinetic
and potential energy.
2.
1. *Distinguish between energy
and temperature
Objective
Target
Page
in SG
p. 279 #914
p.259
#19-21
p.258
#7,8
p.258 #9
p.258 #
10,12
p.258 #25, 11
Textbook
Example
Problem