Spring 2011 Biotechnology & Biofuels Midterm
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Date:
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Directions: Do NOT open this packet until instructed to do so. There should be absolutely NO TALKING during the exam
unless you have raised your hand and have been called on by the instructor. Failure to do so will result in one verbal
warning, and then a failed test grade.
Students should sit on opposite sides of the lab tables for this exam. DO NOT sit together on the same side.
Select the BEST answer to each question from the options given (more than one may sound right, but there is only one
entirely correct answer per question). Be sure to clearly mark your answers on the Scantron sheet. You may write on
your test packet, but only answers on the Scantron will be considered.
You may use one and only one 3x5” note card with your own handwritten note. This notecard must stay on the desk in
front of you at all times.
Exam test taking tips:
Treat each question like a short answer question if you can. Cover the answers, create an answer in your head, and then
match that answer to those given to find the best answer.
If you do not know an answer, skip it and come back later.
Use information from other questions to help you. One question may help you answer another question.
Cross off answers to eliminate and lower possibilities. If you cannot narrow the options to just one, select the answer
that sounds the best to you and makes the most sense.
Read each question AND each option carefully. Do not select an answer until you have read them all!
Good Luck!
C OPYRIGHT C RAIG K OHN, W ATERFORD WI 2011. A VAILABLE FOR PUBLIC USE PROVIDED THE AUTHOR IS CITED .
1. Fossil fuels currently provide more than _______% of all the energy used in the US
a. 95 b. 85 c. 75 d. 65
2. Fossil fuels are formed from…
a. Inorganic elements deep within the earth’s crust
b. The byproducts of human activity on the surface
c. A complex series of chemical reactions conducted in laboratories and refineries
d. The accumulation of plants and animals on the bottom of prehistoric seabeds
3. The accumulation of ______ and _______ turned organic carbon molecules into the hydrocarbons in fossil fuels.
a. Heat, pressure b. Pressure, oxygen c. Oxygen, fire d. Fire, heat
4. What elements are found in hydrocarbons?
a. Hydrogen, carbon, oxygen, and nitrogen
b. Hydrogen, carbon, and oxygen
c. Hydrogen and carbon
d. Just carbon
5. Petroleum is…
a. A blend of many different kinds of hydrocarbons.
b. A blend of hydrocarbons and ethanol
c. A synthetically produced version of natural hydrocarbons
d. A blend of natural and synthetically produced hydrocarbons
6. How are the different products of petroleum (gasoline, kerosene, lubricating oil, etc.) separated from each
other?
a. They are filtered; each product has a different viscosity
b. They are heated; each product has a different boiling point
c. They are centrifuged; each product has a different density
d. None of the above; petroleum is one of many products created from fossil fuels
7. Combustion is a reaction in which
a. A substance is consumed, reducing its matter
b. A substance (along with oxygen) is rearranged into simpler, more stable molecules
c. A substance is burned to create energy
d. A substance is converted into energy
8. Combustion is _________; it ____________ energy
a. Exothermic; absorbs b. Exothermic; releases
c. Endothermic; absorbs
d. Endothermic; releases
9. Fossil fuels ___________ energy when combusted because the energy needed to break the bonds of a
hydrocarbon is ____________ than the energy give off by the formation of bonds in CO2 and H2O.
a. Absorb; greater b. Absorb; less c. Release; greater d. Release; less
C OPYRIGHT C RAIG K OHN, W ATERFORD WI 2011. A VAILABLE FOR PUBLIC USE PROVIDED THE AUTHOR IS CITED .
10. What is responsible for the smog, soot, and carbon monoxide associated with the use of fossil fuels?
a. The hydrocarbon molecule – when completely combusted, there are “leftover” parts that form these
pollutants
b. The combustion reaction does not fully occur in most cases with hydrocarbons, leaving partial
hydrocarbons that form these pollutants.
c. The CO2 produced from the hydrocarbons prevents the combustion reaction from starting
d. Fossil fuels are dirty because they come from the ground.
11. Biofuels tend to burn _________ than fossil fuels because they burn more _____________
a. Dirtier; slowly b. Cleaner; incompletely c. Dirtier; quickly d. Cleaner; completely
12. Why are atmospheric CO2 levels unnaturally high?
a. CO2 is not naturally produced; human activity is adding this molecule to the atmosphere where it never
once existed
b. CO2 is in the atmosphere because of the hole in the ozone layer
c. CO2 used to be produced and used in similar rates; the use of fossil fuels adds CO2 at a rate far faster
than it can be reabsorbed
d. CO2 levels are not a problem right now
13. How does CO2 cause changes to the Earth’s surface temperatures?
a. CO2 absorbs and releases infrared radiation, holding it in the atmosphere longer
b. CO2 forms a shield that traps radiation on the Earth permanently
c. CO2 produces heat when it breaks down in the atmosphere
d. CO2 does not cause an increase in surface temperatures
14. The US accounts for _________% of global carbon emissions despite having only _____% of the world’s
population.
a. 50; 25 b. 50; 5 c. 25; 10 d. 25; 5
15. Ethanol requires _____________ energy to produce than is released when it is combusted.
a. Less b. More c. the same amount of
16. Ethanol produces ____________ carbon dioxide when it is combusted than gasoline.
a. Less b. More c. the same amount of
17. A major disadvantage of ethanol is that it….
a. Has a lower gas mileage (vs. fossil fuels); b. Produces more CO2; c. Is less energy efficient; d. All of the above
18. Compared to petroleum diesel fuel, biodiesel is __________ burning, has ______ emissions, and is ______ toxic.
a. Cleaner; lower; less b. Dirtier; higher; more
c. Cleaner; lower; more
19. A major disadvantage of biodiesel is that even small amounts of __________ will affect the performance of it.
a. Oxygen b. CO2 c. Water d. Weight
20. Biofuels are carbon neutral, meaning –
a. They don’t produce CO2 b. They produce less CO2 than they absorb
c. They produce more CO2 than they absorb d. They absorb the CO2 they release
C OPYRIGHT C RAIG K OHN, W ATERFORD WI 2011. A VAILABLE FOR PUBLIC USE PROVIDED THE AUTHOR IS CITED .
21. How does a diesel engine convert the energy in fuel into motion?
a. The fuel flows past gears that are connected to the axels; the movement of fuel turns the gears.
b. The fuel is heated which causes it to expand, pushing against a piston which moves the wheel. As the
fluid cools it contracts, pulling the piston with it
c. The fuel is compressed, and this compression heats it to the point of combustion. When the fuel
combusts, it pushes a piston in a cylinder down, turning the driveshaft.
d. The fuel is mixed with air in the cylinder. A spark from a spark plug ignites the fuel-air mixture, causing a
combustion reaction which pushes the piston down, turning the drive shaft.
22. What is the main difference between diesel and gasoline engines?
a. Diesel fuel is primarily made from renewable sources, while gasoline is not
b. Gasoline engines do not produce pollution
c. Diesel engines do not produce pollution
d. Diesel engines do not have a spark plug
23. What makes a diesel engine so efficient?
a. The fact that the air is compressed concentrates the amount of oxygen in the combustion reaction
b. Diesel fuel is a more easily combustible fuel
c. A diesel engine is made more efficient because of its spark plug
d. Diesel engines are more efficient because they can be run on renewable fuel
24. Biodiesel is fuel…
a. Made by reacting a plant oil or animal fat with methanol and a catalyst
b. Created using the byproducts of ethanol production
c. Made from the byproducts of petroleum production
d. That can only be used in cold weather
25. What is transesterification?
a. A chemical reaction in which an alcohol is converted into an oil or fat
b. A chemical reaction in which fat or plant oil is turned into alcohol
c. A chemical reaction in which the carbon groups of an oil are broken into straight chains using an alcohol
d. A chemical reaction in which glycerin is turned into diesel fuel
26. Which of the following is NOT an advantage of biodiesel?
a. It can be used directly in most diesel engine types with only a few modifications
b. It is non-toxic and biodegradable
c. It is far more energy efficient, releasing over 3x as much energy as is needed to produce it
d. It gets higher gas mileage gallon for gallon
27. How much CO2 does biodiesel produce?
a. More than it absorbs
b. Less than it absorbs
c. The same amount as it absorbs
d. More than petroleum diesel fuel
C OPYRIGHT C RAIG K OHN, W ATERFORD WI 2011. A VAILABLE FOR PUBLIC USE PROVIDED THE AUTHOR IS CITED .
28. Which of the following is NOT a disadvantage of biodiesel?
a. It will dissolve or corrode certain kinds of metals, rubbers, and plastics
b. It is more toxic than petroleum diesel
c. It spoils over time
d. It requires far more land to produce than is available to meet the nation’s transportation energy needs
29. After the transesterification reaction with oil, what should we see?
a. A clear-ish layer of yellow biodiesel on top, with dark glycerin on the bottom
b. A clear-ish layer of yellow glycerin on top, with dark biodiesel on the bottom
c. A cloudy mix of biodiesel and glycerin
d. A batch of biodiesel ready to be put straight into an engine
30. What does it mean to “wash” your biodiesel?
a. To allow the biodiesel to sit in the open air as water evaporates from it
b. To treat your biodiesel with petroleum diesel fuel to absorb any impurities
c. To use glycerin (soap) to remove harmful lipids
d. To rinse your biodiesel with water to absorb and remove impurities and un-reacted reagents.
31. What does it mean to “dry” your biodiesel?
a. To allow the biodiesel to sit in the open air as water evaporates from it
b. To treat your biodiesel with petroleum diesel fuel to absorb any impurities
c. To use glycerin (soap) to remove harmful lipids
d. To rinse your biodiesel with water to absorb and remove impurities and un-reacted reagents.
32. As biodiesel dries, it should become….
a. Darker b. Clearer c. Cloudier
d. Thicker
33. Biodiesel is only a partial solution to the energy needs of our nation because…
a. It is less energy-efficient than diesel fuel, releasing less energy than it needs to produced
b. Biodiesel does not work without costly and dramatic changes to diesel engines
c. It produces more CO2 than petroleum diesel fuel
d. Biodiesel requires vast amounts of land to produce enough oil for the transesterification process
34. Biodiesel can become explosive if ___________ materials are used in its production
a. Glass b. Wood c. Plastic d. Ceramic
35. The first diesel engine ran on fuel made from
a. Petroleum b. Corn c. Soybeans d. Peanuts
36. LCA refers to…
a. Living Carbon Assessment
b. Life Cycle Analysis
c. Limited Carbon Awareness
d. Loving Cows Always
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37. The addition of an oxygen atom to the structure of a hydrocarbon would have what impact on the combustion
of that molecule?
a. It would increase gas mileage (or miles driven per gallon)
b. It would decrease harmful emissions like soot, smog, and carbon monoxide
c. It would require a compression engine instead of an engine with a spark plug
d. All of the above
38. Which of the following is shown here:
a. Ethanol
b. Carbon Dioxide
c. Octane (gasoline)
d. Methane
39. Which of the following is shown here:
a. Ethanol
b. Carbon Dioxide
c. Octane (gasoline)
d. Methane
40. Which of the following is shown below:
a. Ethanol
b. Carbon Dioxide
c. Octane (gasoline)
d. Methane
41. High-quality biodiesel should __________ when added to methanol.
a. Completely dissolve
b. Float on top
c. Sink to the bottom
d. Evaporate
42. High-quality biodiesel should ________ when added to distilled water.
a. Completely dissolve
b. Float on top
c. Sink to the bottom
d. Evaporate
C OPYRIGHT C RAIG K OHN, W ATERFORD WI 2011. A VAILABLE FOR PUBLIC USE PROVIDED THE AUTHOR IS CITED .
43. High quality biodiesel should have a pH of ___________
a. 5 b. 6 c. 7 d. 8
44. Text, when seen through a glass jar of biodiesel, should be ________
a. Unreadable b. Partially readable c. Easily readable d. Unseen
45. Currently, CO2 levels in the atmosphere are at just under…
a. 200 ppm b. 300 ppm c. 400 ppm d. 500 ppm
46. Of the following fuels, which has the greatest net gain of energy when produced?
a. Octane b. Ethanol c. Biodiesel d. Petroleum Diesel
47. Octane, when combusted, will produce how much CO2 per molecule?
a. 2 CO2 b. 4 CO2 c. 6 CO2 8 CO2
48. Ethanol, when combusted, will produce how much CO2 per molecule?
a. 2 CO2 b. 4 CO2 c. 6 CO2 8 CO2
49. Who is the inventor of the diesel engine?
a. Rudolph Diesel
b. Randy Gasoline
c. Ralph Ethanol
d. Rudolph T. Raindeere
50. Ethanol is created through which of the following processes?
a. Transesterification b. Respiration c. Fermentation d. All of the above
51. How does the ethanol molecule change if we change the source it is made from?
a. Corn ethanol molecules burn more cleanly than cellulose ethanol molecules
b. Cellulose ethanol molecules burn more cleanly than corn ethanol molecules
c. Corn ethanol molecules burn more completely than cellulose ethanol molecules
d. Cellulose ethanol molecules burn more completely than corn ethanol molecules
e. None of the above; ethanol molecules are the same regardless of their source
52. Which of the following is the chemical formula for ethanol?
a. CH3CH2OH b. C8H18 c. C6H12O6 d. Any of these could be ethanol depending on the source
53. One molecule of sugar will yield ___ molecules of ethanol and ___ molecules of CO2
a. 1;1 b. 2;2 c. 1;3 d. 3;1
54. Ethanol has a lower ______ than gasoline but a higher ______
a. Octane rating; MPG b. MPG; Octane rating
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55. An octane rating is…
a. A measure of how much energy is contained in a fuel
b. A measure of how much a fuel pollutes
c. A measure of the emissions of a fuel
d. A measure of how efficiently a fuel combusts
56. Cellulosic ethanol could reduce greenhouse gas emissions by what percentage?
a. 10-20% b. 30-40% c. 50-60% d. 80-90%
57. The sinking of an ethanol tanker ship (the Bow Mariner) in 2004 caused what major environmental problems?
a. Acid Rain b. A dead zone off the coast of Virginia c. Polluted groundwater d. None
58. Which of the following is the easiest to convert into ethanol?
a. Cellulosic b. Corn grain c. Sugar Cane d. None of the above; all require the same process
59. Why is most of the ethanol produced in the US made from corn grain?
a. It is the easiest crop to ferment into ethanol
b. It is the most abundant source of ethanol on the planet
c. It is easier to ferment than cellulosic ethanol but more abundant than sugar cane in the US
d. All of the above
60. In ethanol, a feedstock is…
a. The ultimate source of ethanol (e.g. corn or sugar cane)
b. The type of organism used for fermentation
c. The method in which an ethanol crop is harvested
d. The byproducts of fermentation that are fed to cattle
61. Why is cellulosic ethanol considered the most promising source of biofuel in the future?
a. It is the easiest to ferment
b. It is the easiest to grow
c. It is the most abundant potential fuel source on the planet
d. All of the above
62. How does fermentation differ from respiration?
a. Fermentation does not require oxygen to occur
b. Respiration does not produce ethanol
c. Fermentation does not produce CO2
d. All of the above
e. Only A and B
63. Yeast can convert carbohydrates into ethanol because they produce _____ that can break down carbohydrates
into simple glucose molecules and can convert glucose into ethanol
a. Acids b. Enzymes c. Bases d. Fats
64. Define saccharification in corn ethanol production:
a. Chopping long starch molecules into individual glucose molecules
b. Soaking the corn kernels before processing them
c. Converting the sugars in a corn kernel into ethanol
d. Separating the cellulose in corn from lignin and hemicellulose
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65. What is the primary difference between wet-milling and dry-milling of corn grain ethanol?
a. Saccharification b. Steeping c. Fermentation d. Pretreatment
66. Why would an ethanol producer choose dry-milling over wet-milling?
a. It is cheaper
b. It is more flexible
c. Its ethanol has a higher MPG
d. Its ethanol has a higher octane rating
67. Cellulose is a polymer of glucose; what is a polymer?
a. The same substance in a different chemical state (e.g. solid vs. liquid form)
b. A partially digested form of a natural substance
c. A type of natural “glue” that holds a molecule together
d. A long chain of repeating molecules
68. Cellulose can be consumed by ruminant cattle because they are able to _______ before digesting it
a. Grind it b. Hydrolyze it c. Ferment it d. All of the above
69. Why is cellulosic ethanol so much more difficult to produce than ethanol from corn or sugar-cane?
a. Cellulose is wrapped in lignin, which protects it
b. Cellulose is wrapped in hemicelluloses, which protects it
c. Cellulose has bonds that have different orientations, whereas the orientation of the bonds of starch are
all the same
d. Cellulose requires more and different enzymes than starch in order to be completely broken down
e. All of the above
70. The “unwrapping and unpacking” step of ethanol production from cellulose is known as…
a. Biomass Production
b. Pretreatment & Hydrolysis
c. Sugar Fermentation
d. Biofuel Processing
71. What is the most expensive step of ethanol production from cellulosic sources?
a. Biomass Production
b. Pretreatment & Hydrolysis
c. Sugar Fermentation
d. Biofuel Processing
72. Which feedstock use would reduce greenhouse gas emissions the most (through its overall LCA)?
a. Sugar cane b. Corn c. Cellulosic d. All of the above would be the same
73. Which feedstock would provide the largest available fuel source?
a. Sugar cane b. Corn c. Cellulosic d. All of the above would be the same
74. Which step is the biggest obstacle facing cellulosic ethanol?
a. Biomass Production
b. Pretreatment & Hydrolysis
c. Sugar Fermentation
d. Biofuel Processing
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