CHEM 110 Name__________________

EXAM # 2 F Topic 5, 6, 7 See lecture schedule for pages (100 points)

Multiple Choice: (2 points each)

CHAPTER 8

_____1. Which of the following is NOT a property of alkanes? (see also p.365)

a) alkanes are covalent molecules

b) the most important chemical property is that they burn

c) the density is greater than water

d) boiling points increase with length of the carbon chain

_____2. Which of the following is NOT an example of an aromatic compound?

a) benzene

b) cyclohexane

c) toluene

d) benzopyrene

_____3. Which of the following is NOT an example of an organic halide?

a) DDT

b) Freon-12

c) PVC

d) MTBE

CHAPTER 9

_____4. Low density polyethylene is composed of:

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

b) primarily highly branched, nonlinear chains of polyethylene in a diffuse packing arrangement

c) a mixture of polyethylene and polystyrene

d) polyethylene with low density plasticizers added to increase density

_____5. The monomer used to make PVC 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) breaks long carbon chains into smaller chains

c) forms links between polymer chains

d) links all chains into one long chain

_____7. The molecule most commonly split out between monomers to make a condensation polymer is:

a) H2O

b) NH3

c) HCl

d) H2S

 

_____8. The greatest hazard in using plastics in home building materials and furnishings is that some - see p. 271:

a) poison children who eat them

b) cause cancer

c) are slippery

d) form poisonous gases when burned

CHAPTER 16

_____9. Which of the following is not produced during photosynthesis?

a) energy

b) oxygen

c) carbohydrates

_____10. The conversion of phosphate rock and bone to "super phosphate" was significant because it:

a) increases the phosphorus content of the rock or bones

b) makes the material more soluble

c) incorporated phosphorus from the atmosphere

d) did all of the above

_____11. Which form of nitrogen is NOT used by plants:

a) urea

b) anhydrous ammonia

c) nitrous oxide

d) ammonium nitrate

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

a) water soluble

b) synthetic

c) fat soluble

d) synthesized in the liver

_____13. Organophosphorus pesticides are generally more __?____ than DDT.

a) potent

b) more stable in the environment

c) insect resistant

d) fat soluble

_____14. Insects are attracted to a piece of sticky paper in great numbers. The paper has probably been treated with:

a) DDT

b) pheromone

c) plutonium

d) parathion

CHAPTER 17

_____15. Animal fats and vegetable oil can be converted to soaps by reaction with:

a) sodium hydroxide

b) sodium hypochlorite

c) sodium bicarbonate

d) sodium phosphate

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

a) ionic/polar head

b) hydrocarbon tail

c) uncharged groups

d) oil

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

a) effectiveness in hard water

b) biodegradable

c) non petroleum based

d) they lack phosphates

p. 163-165

_____18. Chemical reactions are spontaneous when:

a) the process is endothermic

b) the process moves to a higher energy state

c) the process is exothermic

d) the process goes to lower entropy

_____19. Which physical state has the greatest entropy?

CHAPTER 12

_____20. The yield of gasoline from crude petroleum can be increased by:

a) catalytic cracking of lighter fractions

b) catalytic cracking of heavier fractions

c) simple distillation

d) vacuum distillation

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

a) increases octane rating

b) burns cleaner

c) decreases octane rating

d) burns cooler

 

_____22. Catalytic reforming is a process for converting:

a) low-octane rated alkanes into low-octane rated aromatics

b) high-octane rated alkanes into low-octane rated aromatics

c) low-octane rated alkanes into high-octane rated branched alkanes

d) high-octane rated alkanes into low-octane rated branched alkanes

_____23. Oxygen containing additives to gasoline, such as methyl tert-butyl ether or ethanol, improve octane rating in automobile engines.

a) TRUE

b) FALSE

 

_____24. Which statement is false concerning natural gas

a) inexpensive

b) burns cleanly

c) is very dangerous

d) is the most nonpolluting fossil fuel

 

_____25. Control rods in a nuclear reactor are used to:

a) absorb neutrons and slow down fission

b) absorb neutrons and speed up fission

c) release neutrons and slow down fission

d) release neutrons and speed up fission

_____26. A breeder reactor converts:

a) non fissionable U-238 to fissionable U-235

b) non fissionable U-238 to fissionable Pu-239

c) fissionable U-235 to fissionable U-238

d) fissionable U-235 to fissionable Pu-239

 

 

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

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 in your explanation, reactions at the electrodes. 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.

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

Propose a long term method of obtaining the electricity to "plug-in" or to recharge the batteries for the year 2013. Be realistic about what fuel sources or combination of fuels will be available 10 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:

b) (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 2013.

 

 

 

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

 

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

a)(2) What possible problem is described in this article? Be brief in this section.

 

 

b)(4) Describe the processes in the carbon cycle involving carbon dioxide, first in plants, then in soils.

 

 

 

 

c)(3) (Last column) 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.