Name ______________________

CHEM 110

Exam #2 Topics 5, 6, and 7

Multiple Choice: (2 points each)

_____1. An organic compound may be defined as all of the following except:

a) a compound containing carbon

b) a compound of carbon and hydrogen

c) a compound produced by a living organism

d) contains metal ions

_____2. Which of the following is NOT a property of alkanes?

a) all bonding positions are occupied by either carbon or hydrogen

b) the most important chemical property is that they burn

c) are classified as saturated compounds

d) boiling points decrease with length of the carbon chain

_____3. Which of the following is an example of an aromatic compound?

a) carbon tetrachloride b) diethylether c) isopropyl alcohol d) DDT

_____4. High density polyethylene is composed of:

a) a mixture of polyethylene and polystyrene

b) primarily highly branched, non-linear chains of polyethylene in a diffuse packing arrangement

c) primarily linear, unbranched chains of polyethylene in a close packing arrangement

d) polyethylene with high density plastizers added to increase density

_____5. The monomer used to make Teflon is:

a) H2C=CH2 b) Cl2C=CH2 c) H2C=CHCl d) F2C=CF2

_____6. In the vulcanization of rubber, sulfur:

a) is inserted into the carbon chain

b) forms cross links between polymer chains

c) breaks long carbon chains into smaller chains

d) links all chains into one long chain

_____7. In making the condensation polymers of nylon and polyester, which functional group on the monomer is in COMMON with both:

a) hydroxyl group b) carboxylic acid

c) amino group d) polyamide

_____8. Which type of plasticizer is now banned from use:

a) polychlorinated biphenyls (PCB)

b) biphenyl

c) phthalate esters

d) DDT

_____9. Which of the following IS produced during photosynthesis?

a) energy b) carbon dioxide c) carbohydrates d) water

_____10. Which of the following forms of phosphate is most soluble in water and thus more available to plants?

a) animal bones

b) super phosphate

c) phosphate rock

d) teeth from fish

_____11. Which form of nitrogen is used by some plants in conjunction with bacteria to make nitrate ions:

a) urea c) nitrogen dioxide

b) nitrous oxide d) nitrogen gas

_____12. DDT is biomagnified in living organisms because it is:

a) water soluble c) fat soluble

b) chemically reactive d) synthesized in the liver

_____13. Organophosphorus pesticides are generally more ______ than DDT.

a) easily broken down c) persistent

b) insect resistant d) water soluble

_____14. Which of the following is NOT considered to be a biological insect control

a) pheromones b) carbamate c) juvenile hormones d) bacillus Thuringiensis (Bt)

_____15. Laundry detergents contain all of the following EXCEPT:

a) optical brighteners c) hard water

b) alkyl benzene sulfonate d) zeolites as builders

_____16. In cleaning, soap acts as a bridge between "dirt/oil" and water. Which part of the soap molecule interacts with the oil?

a) ionic end b) hydrocarbon end c) charged groups d) water

_____17. The major environmental disadvantage of ABS detergents over LAS detergents is:

a) non biodegradable c) biodegradable

b) non petroleum based d) they lack phosphates

_____18. The statement that expresses disorder or randomness of a system, is another way of expressing:

a) the tendency of the system to move to a lower energy state

b) entropy of a system

c) Boyle's law

d) a non spontaneous process

_____19. The process of burning coal is

a) exothermic b) endothermic c) catalysis d) entropy

_____20. The best yield of gasoline from crude petroleum distillation towers is from:

a) catalytic cracking of lighter fractions

b) lower boiling fractions at the bottom of the column

c) simple distillation

d) lower boiling fractions at the top of the column

_____21. In general, a lower proportion of branched chain hydrocarbons in a gasoline formulation:

a) increases octane rating c) burns without knocking

b) decreases octane rating d) is formulated by catalytic reforming

_____22. Which liquid fuel, by fractional distillation of petroleum, is obtained at the highest boiling point?

a) asphalt b) gasoline c) kerosene d) heating oil

_____23. Which statement is true concerning natural gas

a) is very expensive

b) is very dangerous

c) produces the least amount of carbon dioxide of any fossil fuel

d) is the most polluting fossil fuel

_____24. Oxygen containing additives to gasoline, such as methyl tert-butyl ether or ethanol, decrease octane rating AND reduce CO emissions in automobile engines.

a) TRUE b) FALSE

_____25. When control rods in a nuclear reactor are raised out of the reactor, this causes

a) more absorption of neutrons and slows down fission

b) less absorption of neutrons and speeds up fission

c) release of neutrons and slows down fission

d) release of neutrons and speeds up fission

26. In making a photovoltaic cell, very pure silicon is doped with a small amount of gallium, the resulting crystal:

a. is a complete solar cell b. donates electrons

c. accepts electrons d. is a battery

27. See p. 156, 170, 333, 489-491. Some of the major amounts of synthetic chemicals, sulfuric acid, ammonia, and nitric acid are used to produce fertilizer to produce enough food to keep pace with population growth.

Write a series of chemical reactions (use formulas, as much as possible, or names) starting all the way back with basic RAW materials to synthesize the fertilizers. Some require SEVERAL steps, be sure to show how each element or compound is obtained starting with the RAW material. The first element or compound is then used to synthesize something else needed in the reaction, etc.

The basic RAW materials are:

water

nitrogen and oxygen elements from the air

propane (source of hydrogen element p. 491)

phosphate rock

sulfur as an element (p.333).

Show the reactions steps to make the fertilizer compounds below as the final products, starting with the RAW materials, for example if you need hydrogen, you must start with propane as the raw material:

For example, if you wanted to make carbonic acid:

Start with carbon in coal, the raw material, and react with oxygen from air, a raw material, to make carbon dioxide:

C + O2 ---> CO2

then take the carbon dioxide and react it with water, a raw material, to make carbonic acid:

CO2 + H2O ---> H2CO3

Do all of the above for the two fertilizer components listed below.

a) (4) ammonium nitrate:

b) ( 2) super phosphate:

28. (4) Iodine -131 is a radioactive isotope produced in fission reactions and released in atmospheric atomic bomb testing during the 1950's and 60's, and during the Chernobyl accident. The half-life is 8.1 days. If a 100 g sample of I-131 was released , how much will still be present in 24.3 days? See p. 125-126 for a method to figure out the answer.

29. During the 80's and 90's there has been periodic discussion about using battery/electric automobiles to solve air pollution problems and eventual oil shortages (pp.274-275).

a. (5) List some advantages and disadvantages of the electric car.

b. (6) Explain how the lead/acid battery (p. 207) OR the Fuel Cell works (p. 403-405) Use names of elements, compounds, oxidation, reduction, reactions at the electrodes, in your explanation. Choose ONE of the above.

30. Electric cars may also reduce the amount of carbon dioxide released, depending upon how the electricity is obtained. Electric cars are now a reality. Although electric cars themselves will not produce any or very little pollution, the electricity for the batteries must be obtained from somewhere.

(10 ) List and discuss five possible alternate energy sources which do not produce carbon dioxide gas as a by product.

31. Propose long term mix of methods of obtaining the electricity to "plug-in" or to recharge the batteries for the electric car for the year 2015. Be realistic about what fuel sources or combination of fuels will be available 15 years from now ( you can not get rid of fossil fuels this fast). This discussion should make use of what you have learned in Chaps 12 and 13. Include BOTH items below:

a) (4) List and discuss your best guess of a mix of sources of fuels or other means to produce the electricity needed for the electric cars by 2015.

b) (4) What are the environmental impacts/pollution of making electricity by the methods suggested above.

32. New York Times "Droughts Linked To Warming…." - Article follows.

b)(4) Describe the processes in the normal carbon cycle involving carbon dioxide, etc. in plants ( see p. 44-46). Then describe the carbon cycle and carbon dioxide as described in the article in soils - key in on the statement of "decomposition" - see p. 48.

c)(3) (Last section) Explain in detail how dry soil may contribute to excess release of carbon dioxide in normally wet soils.

NY Times, "Droughts Linked to Warming Might Speed Climate Change" by James Glanz Copyright New York Times Company Jan 11, 2001

Droughts caused by global warming could set off a biochemical process in northern soils that would release large amounts of carbon dioxide into the air

and possibly speed changes in the climate, researchers are reporting today in the journal Nature.

The researchers, led by Dr. Chris Freeman of the University of Wales in Bangor, said the increase in droughts predicted by some climate models could

abruptly activate a dormant enzyme in moist, peaty northern soils, triggering decomposition of their organic matter.

This decay would release large amounts of carbon dioxide, a ''greenhouse gas'' thought to cause global warming. The soils are believed to hold 460

billion tons of carbon, or about 60 percent of the amount in the atmosphere as carbon dioxide.

''It is an enormous reservoir that potentially can be released into the atmosphere as another climate change factor,'' said Dr. Robert G. Wetzel, a

professor of biological sciences at the University of Alabama in Tuscaloosa.

Dr. Wetzel, who was not involved in the research, said the mechanism identified by Dr. Freeman ''would accelerate the release from this enormous

pool.''

But he and other scientists cautioned that the possibility outlined in the study depended on predictions based on uncertain climate models.

Dr. Sandra Brown, an ecologist, said, ''The best predictions I've seen say it will be a warmer and drier climate.'' But Dr. Brown added, ''I always worry

when I see these papers making broad extrapolations across the entire world.''

Dr. Brown, of Winrock International, a private environmental organization in Arlington, Va., is a member of the Intergovernmental Panel on Climate

Change, an organization of hundreds of scientists that was created by the United Nations.

Still, several scientists said that the findings would make it even more urgent to try to reduce emissions of greenhouse gases. Late last year at The

Hague, negotiations on a worldwide treaty to reduce global warming collapsed in part because of disagreements over the role of natural ecosystems

like forests in sopping up carbon dioxide from the atmosphere and reducing warming.

The new study, said Dr. Peter Frumhoff, an official of the global environmental program at the Union of Concerned Scientists, who was present during

the negotiations at The Hague, emphasized ''the need to be taking a precautionary approach and moving forward quickly with reducing atmospheric

concentrations of greenhouse gases.'' The organization backs efforts to limit emissions of the gases.

Other scientists did not dispute that assessment but said the results demonstrated the uncertainties in models of the global carbon cycle.

As if to underline that point, a second study published in the same issue of Nature suggested that under some circumstances higher amounts of carbon

dioxide in the atmosphere could inhibit decomposition of material in grassland soils, presumably enhancing carbon storage there.

Any direct implications for the earth's climate will not be known until that effect can be studied longer, said the authors of the study, who include Dr.

Shuijin Hu of the department of plant pathology at North Carolina State University and Dr. Christopher B. Field, a plant biologist at the Carnegie

Institution of Washington, at Stanford University.

''It reminds us that there are still surprises,'' said Dr. Bruce A. Hungate, an ecologist at Northern Arizona University who was not involved in the work,

''that we don't completely understand all the dynamics that control atmospheric CO2 concentration.''

About half of carbon emissions are eventually absorbed by natural carbon sinks in the oceans and on land. The rest of the carbon remains in the

atmosphere. On land, it is stored when plants grow, die and decay into organic matter in the soil. When that organic matter finally decomposes,

nutrients like nitrogen are released in forms that another generation of growing plants can absorb, and the carbon escapes into the atmosphere as

carbon dioxide.

In experiments at the University of Wales, Dr. Freeman and his co-authors -- Dr. Hojeong Kang, now at the University of Wisconsin, and Dr. Nick Ostle,

now at the Centre for Ecology and Hydrology at the Natural Environment and Research Council in England -- studied the biochemistry of northern

peat land soils, which make up about 6 percent of the earth's land, including wetlands, tundra and other moist soils.

The team found that within those soils, the action of an enzyme called phenol oxydase could trigger decomposition of the stored organic matter. But

the enzyme is normally dormant because the water in those soils keeps them free of oxygen, which the enzyme needs to function.

But frequent droughts could dry the soil and let oxygen in. The enzyme would then begin decomposing organic matter; it would also break down

compounds that inhibit the activity of other enzymes, leading to a sort of chain reaction.

Dr. Hu and Dr. Field's research found that increased carbon dioxide levels over several years led indirectly to a starvation of microbial activity in

grassland soils, lowering decomposition rates. But both scientists said that over longer periods, the effect could also reduce plant growth, canceling any

enhancement of the soil's ability to store carbon.

''The ecosystems are big players, but they're almost certainly not going to save the day and result in a situation where emissions cuts aren't necessary,''

Dr. Field said.