Body

Chem 100 Final Exam

December 17, 2001

Part II-- Multiple Choice

50 questions, 2 points each, 100 points

A periodic table is on the last page.

1. Lightning and electrical storms are an important environmental source of
- a. CO
- b. CO₂
- c. Nitric Oxides xxxxxxxxxxxx
- d. SO₂
2. The ozone layer is
- a. beneficial because it absorbs IR light
- b. beneficial because it absorbs UV light xxxxxxxxxxxx
- c. beneficial because it reacts with CFC'S
- d. undesirable because ozone causes respiratory ailments
3. Together, Oxygen and Nitrogen represent what percentage of the atmosphere?
- a. 20% (excluding water vapor)
- b. 50% "
- c. 80% "
- d. 99% " xxxxxxxxxxx
4. The nitrogen you breathe as you inhale air
- ( a golden oldie from the first exam)
- a. plays no significant chemical role in your body xxxxxxxxxxxxxxxxxx
- b. is converted by your body to ammonia (NH₃)
- c. is used by your body to create proteins
- d. is converted in your body to Nitrogen Oxide
5. In a chemical reaction (another golden oldie)
- a. The mass of reactants = the mass of products xxxxxxxxxxxxxxx
- b. The number of reactant molecules = number of product molecules
- c. Volume of reactant = volume of products
- d. The reactants are chemical elements and the products are chemical compounds
6. In the metric system, a milligram contains how many grams?
- a. 0.001 b. 0.1 c. 1 d. 1000 e. 454
- answer is A
7. Which type of radiation possesses the most energy (per photon)
- a. red light b. blue light c. ultraviolet light d. infrared light
- answer is C
8. An atom of oxygen (Atomic Number 8) has how many outer electrons?
- a. none b. two c. four d. six e. eight
- Answer is D
9. The element Se (atomic number 34-- see periodic table on the last page)
- a. is likely to form a +2 Ion
- b. is likely to form a -1 Ion
- c. is likely to be very inert
- d. probably forms a compound H₂Se with Hydrogen xxxxxxxxxxxxx
- e. probably has chemical properties most similar to those of neighboring elements As (atomic number 33) and Br (atomic number 35)
10. A covalent chemical bond
- a. involves the loss of electrons to form a cation
- and the gain of electrons to form an anion
- b. involves the transfer of electrons from the cathode to the anode
- c. involves the sharing of two electrons by two atoms xxxxxxxxxxxxxxxxxx
- d. requires the presence of at least one oxygen atom in the compound.
11. Which of these pairs species best illustrates amphoterism (is an amphoteric substance)
- A. CO and CO₂
- B. O₂ and O₃ xxxxxxxxxxx
- C. ²³⁵U and ²³⁸U
- D. H₃C-O-CH₃ and CH₃-CH₂-OH
12. The chemical O-H bond is water
- a. is polar, with the oxygen end being more negative xxxxxxxxxxxxxxxx
- b. is polar, with the oxygen end being more positive
- c. is ionic
- d. is nonpolar and the H and O ends show no charge
13. Reverse osmosis can be used to desalinate sea water. In this process
- a. the solute evaporates and is condensed
- b. the salt flows through a semipermeable membrane
- c. water flows though a semipermeable membrane xxxxxxxxxxxxxxxx
- d. the sodium ions are trapped on an ion exchange column
14. A solution has a pH of 4.0. Which statement is true
- a. adding hydrochloric acid will raise the pH
- b. placing the solution in a limestone container would raise the pH xxxxxxxxxxxxxxxxx
- c. adding additional pure water would lower the pH
- d. you would need to lower the pH below 1.0 before you could expect fish to live in it.
15. Water is sometimes called the universal solvent. However it is unable to dissolve any
- significant amount of which of these species:
- a. nitrogen gas
- b. oxygen gas
- c. hexane and other hydrocarbons xxxxxxxxxxxxxxxx
- d. ionic compounds
16. Hard water is generally caused by
- a. reaction with soap
- b. dissolved calcium xxxxxxxxxxxxxxxxxxx
- c. acid rain
- d. lead or cadmium ions
17. A solution that contains 1 milligram of lead in 1 million grams of water
- a. has a lead concentration of 1.0 ppm
- b. has a lead concentration of 1.0 ppb xxxxxxxxxxxxxxxxxxx
- c. has a lead concentration of 1.0 x 10^-6 Molar
- d. has a lead concentration of 1.0 x 10^-9 Molar
18. An aqueous solution of the ionic compound Magnesium Chloride, MgCl₂, will contain
- a. Magnesium Chloride molecules in solution
- b. Mg²⁺ ions and Cl^- ions in solution xxxxxxxxxxxxxxxxxx
- c. Mg²⁺ ions and Cl₂-2 ions in solution
- d. Mg metal and Cl₂ gas in solution
19 . The unit of energy most often associated with chemical reactions is
- a. Joule xxxxxxxxxxxxx
- b. Celsius
- c. Exotropic
- d. Mole
20. Which of the air pollutants below is generally associated with coal as a fuel
- and is much less likely to be associated with petroleum based fuels?
- a. carbon dioxide
- b. carbon monoxide
- c. sulfur dioxide xxxxxxxxxxxxxxxxxxxxx
- d. nitrogen oxides
21. A nuclear power plant for electricity generally has large cooling towers mainly
- a. to condense steam that passes through turbines xxxxxxxxxxxxxxxxxxxxx
- b. to cool the reactor core to avoid overheating
- c. to remove excess neutrons, avoiding a chain reaction
- d. to remove radioactive isotopes from the exhaust stream of the reactor
22. Gasoline for automobiles often contains 5-15% ethanol or ethyl alcohol, C₂H₅OH, because
- a. Petroleum is a mixture of compounds including alcohols and hydrocarbons. Distillation of petroleum thus produces a mixture of hydrocarbons and alcohol.
- b. Routine processing (catalytic "cracking") of petroleum converts some of the hydrocarbons into alcohols
- c. Ethanol is added because it provides much more energy than hydrocarbons-- it is the easiest way to boost the octane rating of gasoline
- d. Ethanol is much less expensive than petroleum; adding it makes fuel less expensive.
- e. Added ethanol can reduce the amount of CO produced when cars burn gasoline xxxxxxxxxxxx
23. The notation ²³³₉₀Th tells us that this form of thorium (Th) ...
- a. contains 90 neutrons in the nucleus
- b. contains 143 neutrons in the nucleus xxxxxxxxxxxxxxxxxx
- c. contains 90 electrons in the nucleus
- d. contains 90 Thorium atoms in one thorium molecule
24. Which reaction below is typical of the reaction that powers a nuclear power plant?
- (All of the equations are balanced and refer to real reactions.
- Sorry the subscripts and superscripts for isotopes don't line up correctly.)
- a. ²³⁵₉₂U -----> ²³³₉₀Th + ⁴₂He
- b. ²³⁵₉₂U + ¹_on ----> ¹⁴¹₅₆Ba + ⁹²₃₆Kr + 3 ¹_on
- c. ²³⁸₉₂U + ¹n_o -----> ²³⁹₉₄Pu + 2 ⁰_-1e
- d. ²₁H + ²₁H---> ⁴₂He
- answer is b (split into two nuclei and extra neutrons)
25. Beta radiation is best described as
- a. a high energy Helium nucleus
- b. a high energy form of electromagnetic radiation
- c. a high energy electron xxxxxxxxxxxxxxxxxxx
- d. a long lived radioactive isotope
26. In the formula E=mc²
- a. C is used to refer to concentration
- b. C is the speed of light xxxxxxxxxxxxxxxxxxxx
- c. C is the half life of the isotope
- d. C is an abbreviation for 1000.
27. In a nuclear reactor used to produce electricity in the US, the fuel is likely to be
- a. uranium, enhanced in the U-235 isotope xxxxxxxxxxxxxxxxxxx
- b. uranium, enhanced in the U-238 isotope
- c. plutonium
- d. enclosed in cadmium control rods
28. The used fuel from a nuclear reactor
- a. is highly radioactive; will need to be stored away from people for thousands of years xxxxxxxx
- b. is mildly radioactive, but the radiation only lasts for a period of about five years and then the used fuel can be safely disposed of in an ordinary landfill.
- c. consists only of the unfissionable isotopes (like ²³⁸U) that are not radioactive
- d. is normally processed, recycled, used indefinitely; thus there is no waste to store
- e. since a reactor converts mass entirely into energy (E = mc²), there is no waste remaining from normal operation.
29. The half life of C-14 is 5700 years.
- Which of these statements about the Carbon dating process is NOT true?
- a. C-14 is continuously formed in the atmosphere
- b. After 11400 years, a C-14 containing sample will have lost 3/4 of its radioactivity
- c. Wood from trees growing near busy highways often show ages (by C-dating) much older than the known age of the trees.
- d. Coal and other fossil fuels cannot be reliably dated by this technique
- e. none (statements a-b-c-d are all correct) xxxxxxxxxxxxxxxxxxxxxxx
30. Which of these materials is not a polymer
- a. a protein
- b. cellulose
- c. a polyamide
- d. an amino acid xxxxxxxxxxxxxxxxxxxxx
31. Which compound is least likely to be the starting material for forming a polymer?

31 answer= c (only one functional group, can't form a string)

32. One property of most commercial plastics that makes recycling practical is
- a. The starting material is so expensive that recycling greatly reduces the cost of materials
- b. Most commercial plastics are thermoplastic and can be reformed into new objects
  - (b correct)xxxxxxxxxxxxx
- c. The energy costs of recycling is much less than the energy cost in making new plastics
- d. These plastics are biodegradable and most can be easily composted and used to improve soil on farms, lawns and golf courses.
33. The major molecular difference between LDPE and HDPE forms of polyethylene
- a. HDPE is made by a condensation reaction while LDPE is made by an addition reaction
- b. HDPE is basically a linear polymer while LDPE is more highly branched xxxxxxxxxx
- c. LDPE is low density because it is a foam, containing many tiny gas bubbles
- d. LDPE has a low density carbon atom chain; HDPE is a polymer with a Silicon chain
34. The pain killer associated with chewing on willow bark (described in the textbook) is
- a. a chemical analog of morphine and heroin
- b. led to the development of aspirin xxxxxxxxxxxxx
- c. is called a placebo
- d. is a hormone produced by the body in response to chewing and saliva
35. The amino acid lysine is said to be an essential amino acid. The term essential means
- a. lysine is found in the protein in our body
- b. lysine is chemically an amino acid, but it is not found naturally in proteins
- c. that the human body can synthesize lysine from other species
- d. that the human body cannot synthesize lysine from other species xxxxxxxxxxxxx
36. Fats and Oils in our diet are generally
- a. proteins
- b. esters xxxxxxxxxxxxx
- c. petroleum products
- d. saturated solutions
37. When we talk about a Generic Drug, the word Generic means
- a. the drug can be sold without a prescription
- b. the drug can be used to treat a very wide range of medical conditions
- c. the drug is manufactured by a company that does not own the patent on the drug
- c is correct xxxxxxxxxxxxx
- d. the drug is an analog (chemical modification) of another drug that is already approved by the FDA.
38. Modern drug development often relies on finding a precise fit between an active site that is associated with a disease condition and a proposed chemical treatment.. This concept is often referred to with the phrase
- a. mirror images
- b. lock and key model xxxxxxxxxxxxx
- c. trial and error approach
- d. orphan drug approach
39. The Hall Process for the production of Aluminum was developed in Ohio. Which of the steps below is NOT a feature of the Hall process.
- a. Aluminum ion is reduced to form Aluminum Metal
- b. Aluminum metal is produced at the cathode of an electrical cell
- c. The electrolytic cell is filled with an aqueous solution of aluminum salts
- c-- cannot use water--xxxxxxxxxxxxx
- d. The cost of electricity is the major expense in the production of aluminum
40. Which of these is classified as a rechargeable electrical cell
- a. a solar cell
- b. the electrolysis of water and then burning the hydrogen for energy
- c. the lead acid battery in a car xxxxxxxxxxxxx
- d. a hydrogen fuel cell
41. You could N-dope a piece of the semiconductor silicon (atomic number 14)
- a. by purification to remove almost impurities
- b. by deliberating introducing traces of aluminum (At No 13)
- c. by deliberately introducing traces of Arsenic (At No 33)xxxxxxxxxxxxx
- d. by replacing most of the silicon with a metallic element like gallium (at No 31)
42. A standard flashlight battery or alkaline cell contains significant amounts of
- a. lead
- b. cadmium
- d. mercury
- e. zinc xxxxxxxxxxxxx
43. The reaction that provides most of the energy produced by the sun is
- a. the combustion of hydrogen gas
- b. nuclear fission
- c. nuclear fusion xxxxxxxxxxxxx
- d. solar panels
- 44. Most of the CO₂ produced by the burning of fossil fuels
- a. accumulates in the upper atmosphere and acts as a greenhouse gas
- b. is removed by plants through the process of photosynthesis xxxxxxxxxxxxx
- c. is removed by animals through the process of respiration
- d. is removed by catalytic converters or other emission controls required by federal law
45. The nucleus of the atom
- a. has less than 1% of the mass and is less than 1% of the diameter of the entire atom
- b. has over 99% of the mass yet is less than 1% of the diameter of the entire atom
- c. has over 99% of the mass and is more than 99% of the diameter of the entire atom
- d. is electrically neutral, but is surrounded by several shells of negative electrons
- answer is b xxxxxxxxxxxxx
46. A major concern (scenario) associated with a global increase in atmospheric CO₂ is
- a. flooding of coastal cities xxxxxxxxxxxxx
- b. growth of polar ice cap and return of an ice age
- c. increased incidence of skin cancer
- d. decreased O₂ levels and the inability of animals (and man) to breathe safely
47. Avogodro's Number is
- a. the number of atoms in a mole of any element xxxxxxxxxxxxx
- b. the number before a species in a balanced chemical reaction
  - like the 2's in .... 2 H₂ + O₂ ---> 2 H₂O
- c. the number of protons associated with an element
- d. the average atomic weight of an element
48. The Washington Monument (1885) was capped with a very expensive 6 pound pyramid of a
- metal that represented a technological marvel. the metal was
- a. Gold from the California Gold Rush Fields
- b. Uranium
- c. Aluminum xxxxxxxxxxxxx
- d. Radium
49. The term alloy means
- a. a metal mixture of copper with another element such as zinc or tin
- b. a metallic element in its pure state
- c. an element that is naturally found as native metal, such as gold
- d. a species that contains to or more metallic elements xxxxxxxxxxxxx
50. The bronze age is most closely associated with
- a. the element gold
- b. the element copper xxxxxxxxxxxxx
- c. the element iron
- d. the development of sun block and tanning oils