MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

Transcription

1 Exam 2 CHEM 1100 Summer School 2017 PRACTICE EXAM Name MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) The heat of combustion of ethane, C 2 H 6, is 1560 kj/mol. What is the heat of combustion of ethane, in kj per gram? A) 195 kj/g B) 51.9 kj/g C) kj/g D) kj/g 1) 2) The conclusion that it is impossible to completely convert heat into work without making other changes in the universe is A) the concept that increasing entropy characterizes all changes in the universe. B) based on erroneous observations. C) another way of stating that all energy is either thermal energy or heat. D) the second law of thermodynamics. 2) 3) In an exothermic chemical reaction A) heat is released as the reaction proceeds. B) the mass of the products is greater than the mass of the reactants. C) heat is absorbed as the reaction proceeds. D) the mass of the products is less than the mass of the reactants. 3) 4) The heat of combustion of methane, CH 4, is 50.1 kj/g. How much heat would be generated if 1.00 mol of methane undergoes complete combustion? A) 601 kj B) 804 kj C) 3.12 kj D) 0.32 kj 4) 5) The energy needed to initiate a chemical reaction is called the A) renewable energy. B) heat of combustion. C) bond energy. D) activation energy. 5) 6) How is heat energy used to generate electricity in a modern power plant? A) Heat generates strong magnetic fields through which the wires of a turbine move. B) Heat boils water to make steam, which drives a turbine. C) Heat warms wires causing electrons to move through them more rapidly. D) Heat warms the fins on a turbine, causing them to spin. 6) 1

2 7) Consider the following equation that describes the complete combustion of propane, C 3 H 8. 7) The bond energies are: C H 416 kj/mol; C C 356 kj/mol; O O 498 kj/mol; C O 803 kj/mol; H O 467 kj/mol. Which is the total amount of energy required to break all of the bonds in propane? A) 4396 kj/mol B) 712 kj/mol C) 4040 kj/mol D) 3328 kj/mol 8) Consider the following equation that describes the complete combustion of propane. 8) The bond energies are: C H 416 kj/mol; C C 356 kj/mol; O O 498 kj/mol; C O 803 kj/mol; H O 467 kj/mol. Which is the net energy released on complete combustion of propane? A) kj/mol B) kj/mol C) kj/mol D) kj/mol 9) Which is an advantage of using coal over petroleum as a source of energy in the United States? A) As a solid, coal is easier to transport than a liquid such as petroleum. B) Coal reserves in the United States are far greater than petroleum reserves. C) Carbon makes up a smaller proportion of coal than it does of petroleum. D) Coal is the source of many more different fuels with a wide range of properties than is petroleum. 10) Petroleum (crude oil) is a complex mixture of thousands of substances, the majority of which are A) proteins. B) carbohydrates. C) hydrocarbons. D) natural gases. 9) 10) 2

3 11) Consider these three compounds. 11) Which are isomers? A) I and III only B) I and II only C) II and III only D) I, II, and III 12) Consider these three compounds. 12) Which are isomers? A) I and III only B) II and III only C) I and II only D) I, II, and III 13) A gasoline's octane rating is a measure of the A) pollutants produced by burning the gasoline in a vehicle's engine. B) purity of the gasoline. C) gasoline's resistance to causing knocking in a vehicle's engine. D) energy content of the gasoline. 14) Alternative energy sources are currently being researched in effort to replace our dependence on fossil fuels. Which is not a current research effort in this regard? A) converting coal into gaseous and liquid fuels similar to petroleum products B) obtaining alternative fuels from renewable sources such as garbage C) increasing the use of farm product biomass, such as corn, to produce ethanol. D) reintroducing the use of tetraethyl lead to increase the octane rating of gasoline 15) Which naturally occurring radioactive particles are the largest? A) alpha particles B) beta particles C) gamma radiation D) neutrons 13) 14) 15) 3

4 16) Which is the balanced equation for the fission of U-235? 16) A) B) C) D) 17) Which of these is not a realistic risk associated with nuclear power plants? A) thermal pollution of nearby body of water B) a meltdown from loss of coolant C) a nuclear explosion D) release of radioactivity from spent fuel rods 18) Which is true about radioactivity? Radioactivity A) damages DNA. B) damages white blood cells. C) is used to treat certain cancers. D) All of these choices are true. 19) Which fact is not important when drawing conclusions from C-14 dating? A) C-14 has a half-life of 5,715 years. B) C-14 emits beta particles. C) Dead organisms do not exchange carbon with the atmosphere. D) Living organisms exchange carbon with the atmosphere. 20) Which does not contribute to your annual radiation dose? A) the number of hours you spend listening to the radio B) the amount of time you spend riding in jet planes C) the type of structure you live in D) the number of dental X-rays you get each year 21) What type of radiation is given off in this nuclear reaction? 17) 18) 19) 20) 21) A) alpha B) beta C) gamma D) neutron 22) What type of radiation is given off in this nuclear reaction? 22) A) alpha B) beta C) gamma D) neutron 23) If you have g of radioisotope with a half-life of 5 days, how much isotope would remain after 15 days? A) 12.5 g B) 40.0 g C) 25.0 g D) 13.3 g 23) 4

5 24) The burning characteristics of a gasoline can be improved by converting the octane it contains into isooctane. This conversion requires the use of expensive catalysts such as A) platinum and palladium. B) ultraviolet radiation. C) gold and titanium. D) biological enzymes. 25) In a refinery, the components of petroleum are separated by A) isomerization. B) fractional distillation. C) combustion reactions. D) crystallization. 26) For safety reasons, high-level nuclear waste (HLW) must be contained A) for 10 years. B) for 100 years. C) permanently. D) until it becomes low-level nuclear waste. 27) As compared to high-level nuclear waste, low-level nuclear waste A) is contaminated with smaller quantities of radioactive material. B) has longer half-lives. C) can be disposed of in landfills. D) includes spent fuel rods. 28) The annual radiation dose for most citizens of the United States is between A) 0.25 to 0.50 Sv. B) 0.10 to 0.25 Sv. C) 0 to 0.10 Sv. D) 0.50 to 1.0 Sv. 24) 25) 26) 27) 28) 29) The radioactive decay series of 238 U terminates at which nonradioactive isotope? A) 210 Tl B) 206 Pb C) 210 Bi D) 144 Ba 29) 30) The greatest percentage of background radiation comes from A) nuclear power plants. B) naturally occurring radon. C) medical X-rays. D) living things. 31) Chemical energy is converted directly into electrical energy in A) an automobile's engine. B) a galvanic cell. C) an electrical power plant. D) an electrolytic cell. 30) 31) 5

6 32) Which is the cathode in this galvanic cell? 32) A) the Zn 2+ (aq) ions in the 1 M solution B) the solid silver electrode C) the solid zinc electrode D) the Ag + (aq) ions in the 1 M solution 33) Why can the lead-acid batteries used in cars generate electricity for several years before running down? A) These batteries are used only to generate the electricity that makes the first spark plug "spark." Therefore, they are hardly used at all when a car is started, and never when it is driven. B) The mechanical motion of the engine drives an alternator that generates electricity to recharge the battery. C) The electrons they generate, not the chemical components, provide almost all of the electricity. D) A lead-acid battery is so large that it holds large quantities of the chemicals whose electrochemical interaction creates the electricity. 34) Which type of battery is widely used to store the excess energy generated by windmill farms and solar panels? A) nickel-metal hydride B) alkaline C) lithium ion D) lead acid 35) Which type of widely used battery is not rechargeable? A) nickel-cadmium (NiCad) B) lithium-ion C) zinc-manganese alkaline D) lead-acid (storage batteries) 33) 34) 35) 6

7 36) How does using hydrogen as the fuel in an electric power plant compare with using hydrogen as the fuel in a fuel cell? A) Using H 2 in a fuel cell generates far more heat than burning it in a power plant. B) A fuel cell using hydrogen operates at a higher overall efficiency than would a power plant burning hydrogen as a fuel. C) H 2 used as a fuel in a power plant must be more pure than the H 2 used in a fuel cell. D) Burning H 2 in a power plant produces many more pollutants than using H 2 in a fuel cell. 36) 37) What moves in the salt bridge from the cathode to the anode? 37) A) Cu +2 ions B) electrons C) anions D) Zn +2 ions 38) In an electrochemical cell, the anode is A) never a metal. B) the electrode at which oxidation takes place. C) the material used to connect the two half cells to each other. D) always used up before the cathode. 38) 7

8 39) During the chemical reaction in an electrochemical cell, A) a substance is oxidized and gains electrons. B) oxidation takes place alone, without an accompanying reduction. C) oxidation occurs at the anode. D) electrons travel from the cathode to the anode. 39) 8

9 Answer Key Testname: SS17 EXAM 2 MC SAMPLE 1) B 2) D 3) A 4) B 5) D 6) B 7) C 8) B 9) B 10) C 11) A 12) A 13) C 14) D 15) A 16) C 17) C 18) D 19) B 20) A 21) A 22) B 23) C 24) A 25) B 26) C 27) A 28) C 29) B 30) B 31) B 32) B 33) B 34) D 35) C 36) B 37) C 38) B 39) C 9