ch 6. chm
Ethanol Wood
Ethanol Wood
Using Figure 6.17, in which of the years below was there the largest overabundance of oil, in which the production exceeded consumption?
2015
Neutrons are given the following symbol:
242 Cm 96
Energy is the ability to do ____ or to produce ____.
work; change
Which of the following is not a "clean coal" technology already in use?
"sequestration" to capture and store CO2 before it is emitted into the atmosphere
For similar light intensity, compact fluorescent bulbs use about 25% of the energy of incandescent bulbs. Let's say you replaced a 100-W incandescent bulb with a fluorescent bulb and that your utility charges $0.15/kW-hour. How many dollars would you save in electricity in the 10,000-hour lifetime of the bulb?
$112.50
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?
-2024 kJ/mol
Match each process correctly with the associated energy change.
-Bond breaking ↔ absorbs energy -Bond forming ↔ releases energy
Which of the following options correctly describe the bonding of carbon? Select all that apply
-Carbon typically forms 4 covalent bonds. -Carbon bonds to attain a total of 8 valence electrons. -Before bonding carbon has 4 valence electrons.
Which of the following statements correctly describe the primary uses of the chemical reactions of gasoline? Select all that apply.
-Catalytic cracking is used to overcome the high energy expenditure required for traditional thermal cracking. -Catalytic combination converts multiple small molecules into larger molecules, and it can be used to form polymers.
Match each biofuel with its source materials.
-Corn or cellulose (eg. switch grass, wood, cornstalks) - Ethanol -Decomposing organic matter and sewage - Biogas -Vegetable oils and nut oils - Biodiesel
What are the three components of the "triple bottom line" in business today?
-Fairness to workers -Environmental protection -Profitability
Which of the following are considered exothermic processes? (Select all that apply.)
-Freezing water -Burning a fuel
Which of the following options correctly explain why petroleum has overtaken coal as the largest energy source in the United States? (Select all that apply.)
-It is easier to extract from underground. -It produces more energy per gram than coal.
Which of the following options correctly describe activation energy? Select all that apply.
-Lower activation energy generally results in faster reactions. -Increasing temperature allows more particles to have sufficient energy to overcome the activation energy barrier.
Match the chemical formula with the correct name for each alkane.
-Methane - CH4 -Ethane - C2H6 -Propane - C3H8 -Pentane - C5H12 -Hexane - C6H14 -Heptane - C7H16 -Octane - C8H18
Which of the following statements correctly describe bond energy? Select all that apply.
-The total energy required to break apart a molecule depends on the number and type of bonds. -Bond energy values are always positive.
London dispersion forces _______. (Select all that apply.)
-are intermolecular attractions -are stronger for larger molecules than smaller ones -are much weaker than the covalent bonds within the hydrocarbon molecule
Match each type of chemical formula to the correct description.
-molecular formula ↔ gives the ratio of elements in the compound -structural formula ↔ shows the placement of all atoms in the compound
For similar light intensity, compact fluorescent bulbs use about 25% of the energy of incandescent bulbs. Let's say you replaced a 40-W incandescent bulb with a fluorescent bulb and that your utility charges $0.15/kW-hour. How many dollars would you save in electricity in the 10,000-hour lifetime of the bulb?
.15*(1-.25)*10000*40/1000 = $45
Assume that coal can be represented by the chemical formula C135H96O9NSC135H96O9NS . If 6.00 tons of coal is burned, what mass of nitrogen in the form of NOx gases, is produced by this combustion?
0.044 tons nitrogen
When coal is burned in a power plant, ____ energy is converted into electricity, a form of kinetic energy.
potential
Mercury (Hg) is present in trace amounts in coal, ranging from 50.0 to 200.0 ppb. A typical power plant burns 2.59 million tons of coal per year. Calculate tons of mercury in the coal based on the lower (50.0 ppb) and higher (200.0 ppb) concentrations. Mercury at 50.0 ppb = ____ tons Hg Mercury at 200.0 ppb = ____ tons Hg
0.130; 0.518
A slice of pizza supplies 217 kcal (217 Cal). If a person weighing 140 lb expends 80 kcal per mile when walking at 2.0 miles per hour, approximately how long will it take to use up the calories from the pizza?
1 hour 20 minutes
Click and drag on elements in order Using the attached graph, rank the use of coal, petroleum, hydroelectric, and nuclear power as energy sources in the United States in the year 2000. Place the least used energy source at the bottom.
1. petroleum 2. coal 3. nuclear 4. hydroelectric
According to the label on a soft drink, one serving provides 185 kcal. If all of this energy is used to lift 1.0-kg blocks, how many blocks can be lifted 5.0 meters? Note: 1 J is approximately equal to the energy required to raise a 1-kg block a distance of 10 cm against Earth's gravity.
1.55 X 10^4
Silicon used for solar panels is found to be 99.9999% pure. What is the concentration of impurities in ppb?
1000 ppb
The nuclear fission of U-235 can occur by different pathways. If 3 neutrons is/are absorbed by U-235 to produce 9 neutrons and Kr-92, identify other nucleus that is produced using the boxes and pull-down menu provided.
135 Ba 56
A 1 oz piece of dark chocolate supplies 720. kJ of energy. Convert this to kcal (nutritional calories or Cal) given that 1 kJ = 0.239 kcal.
172 Cal
A coal-burning power plant generates 7.53 × 10^16 J per year. If the coal yields 34.0 kJ/g, how many grams of coal were burned each year?
2.21 x 10^12 g
A coal-burning power plant generates 8.53 × 10^16 J per year. If the coal yields 36.0 kJ/g, how many grams of coal was burned each year?
2.37 x 10^12
The heat of combustion for n-heptane, C7H16C7H16 , is 4817 kJ/mol. How much heat is released if 498 kg of this liquid burns completely?
2.39x 10^7 kJ
If a particular utility burned 6.67 million tons of coal that was 2.00% sulfur by weight, how many tons of sulfur dioxide was emitted?
2.67 X 10^5
approximately what percentage of the electrical energy generated in the united states is produced from nuclear energy?
20%
Identify the element symbol and type the mass number and atomic number using the text boxes and pull-down menu provided below.
24 Na 11
From the data in the table, what dose of radiation (in rem) marks the start of changes likely to occur in blood cells?
25 rems
Given that the average U.S. citizen receives 3,600 μSvμSv of radiation exposure per year, use the data in a table of annual radiation exposure to calculate the percentage of exposure the average citizen receives from a dental X-ray.
3%
If a particular utility burned 8.97 million tons of coal that was 2.00% sulfur by weight, how many tons of sulfur dioxide was emitted?
3.6 x 10^4 tons
To produce the same energy, it takes 1.61 times more coal (by volume) than oil. How many gallons of oil will give you the same amount of energy as 350 pounds of coal. Assume that 1 pound of coal has a volume of 0.144 gallons.
31 gallons 350 x 0.141 = 49.35 --> 49.35/1.61 = 30.65
How much more energy per gram does petroleum combustion yield relative to coal?
40-60%
Consider the following equation that describes the complete combustion of propane, C3H8. 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?
4040 kJ/mol
Carbon is in Group 14 (IVA) and has _____ valence electrons. In order to attain a full octet in its outer shell it will therefore form _____ covalent bonds.
4; 4
Although it is not usually used, Einstein's equation, E =mc^2 applies to chemical reactions as well as nuclear reactions. A combustion reaction released 45.0 kJ when one gram of a reactant was burned. How much of this mass was lost in the process? Report your answer to 3 significant figures. 1 joule = 1 kilogram-meter^2/second^2
5.00 x 10^-10 g
If a person consumes 5.33 × 10^5 kcal in a day and one barrel of oil can produce 3.70 × 10^6 kcal, what is the equivalent of energy consumed per year by that person in terms of barrels of oil?
5.33x10^5 kcal / 3.7x10^6 kcal = 1.441 x 10-1 = about .1441 barrels per day So 365 x .1441 = about 53 barrels per year
The heat of combustion of ethane, C2H6, is 1560 kJ/mol. What is the heat of combustion of ethane, in kJ per gram?
51.9 kJ/g
If a snack cake contains 450 food Calories and Dr. Wattenburger is able to burn 250 Calories by running for one-half an hour, how long must she run to completely burn off the snack cake?
54 minutes
To produce the same energy, it takes 1.61 times more coal (by volume) than oil. How many gallons of oil will give you the same amount of energy as 650 pounds of coal. Assume that 1 pound of coal has a volume of 0.144 gallons.
58 gallons 650 x 0.141 = 93.6 --> 93.6/1.61 = 58.1
The heat of combustion for ethane, C2H6C2H6 , is 47.8 kJ/g. How much heat is produced if 4.65 moles of ethane undergo complete combustion?
6.68 X 10^3 kJ
In this figure, the energy difference (in kJ/) for each fuel is its energy content. Calculate the energy content of Methane in kJ/mol. Express your answer as a positive number.
8.04 X 10^2 kJ/mol hint To convert from kJ/g to kJ/mol, multiply by the molar mass.
The heat of combustion of methane, CH4, is 50.1 kJ/g. How much heat would be generated if 1.00 mol of methane undergoes complete combustion?
804 kJ
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 amount of energy gained on making all the bonds in carbon dioxide and water according to the equation?
8554 kJ/mol
What information can be provided by a computer simulation of a fire in a building? Select all that apply.
A comparison of simulated burn patterns with observed burn patterns Probable temperatures in different parts of the room
What type of radiation is given off in this nuclear reaction?
Alpha
An autopsy performed reveals that the stomach of the deceased contained traces of caffeine, starch grains, and fat. What is the most likely composition of the last meal eaten by the deceased?
Bagel with cream cheese and a cup of coffee
Which of the following is an endothermic process?
Boiling water
Which of the following options correctly describe fats and oils? Select all that apply.
Both fats and oils are triglycerides. Oils are typically found in plants rather than from animal sources.
What is the name of the hydrocarbon C4H10?
Butane
The diagram below shows a simplified version of a fractionating column used in the petroleum industry. The position marked __________ corresponds to the cracker where large molecules are broken into smaller molecules.
C
Using a table of alkanes as your guide, give the chemical formula for the straight-chain (normal) alkane with 12 carbon atoms.
C12H26 https://en.wikipedia.org/wiki/List_of_straight-chain_alkanes
What is the chemical formula for propane?
C3H8
Using a table of alkanes as your guide, give the chemical formula for the straight-chain (normal) alkane with 7 carbon atoms.
C7H16
approximately what percentage of the electrical energy generated in the united states is produced from nuclear energy
Control Rods
Which of the following is not a drawback of using coal for energy production?
Difficult transportation due to instability
All processes either require energy or give off energy. Sort the examples by whether they are exothermic or endothermic.
Exothermic - A mammal metabolizing food - The reaction in a chemical "hot pack" for warming hands in winter. - Burning candle - Setting off a firework Endothermic - water evaporating - the reaction in a chemical "cold pack" for treating injuries - ice melting - photosynthesis -- plants using sunlight to turn CO2 into plant material
True or false: Energy is required to form bonds.
False
True or false: If the DNA found at a murder scene matches that of the suspect, the suspect is unequivocally guilty of murder.
False
True or false: The worldwide oil reserves will soon be depleted.
False
Fuels formed by natural processes such as the decomposition of prehistoric organisms are called ____ fuels.
Fossil
which example is both a type of nuclear radiation and electromagnetic radiation?
Gamma radiation
Which is produced in the greatest amount from a barrel of petroleum?
Gasoline
What is the name of C7H16?
Heptane
Consider these three compounds. Which are isomers?
I and III only
Which argument(s) for the increasing use of solar energy is/are valid? I. Solar cells are becoming cheaper and increasingly more efficient. II. The cost of generating electricity from fossil fuels is increasing. III. Limited and uncertain supply and the increasing requirements for pollution control are raising the cost of fossil fuels.
I, II, and III
Which of the following options best describes isomers?
Isomers contain the same number and type of atoms, but they are connected in different ways.
During an energy conversion, what happens to the energy that is "lost"?
It becomes kinetic energy of random motion of the surrounding molecules.
Which is not a known advantage of natural gas over other fossil fuels?
It is far more abundant than any other fossil fuel
What are the biggest advantages of natural gas as a fuel source? Select all that apply.
It produces almost no sulfur oxides. It leaves no ash residue.
Which of the following options correctly describes an exothermic reaction?
It releases more energy by forming product bonds than is needed to break reactant bonds.
What is the modern metric unit of energy?
Joules (J)
Which of the following might indicate that a hit-and-run incident was deliberate rather than accidental? Select all that apply.
Lack of skid marks on the street near the location of the body Fingerprints on the victim's wrists, ankles, and/or socks
What compound makes up the majority of natural gas?
Methane
Rank the hydrocarbons below in order from lowest to highest boiling point.
Methane Propane Pentane Octane
Which of the following are common sources of energy in the United States? Select all that apply.
Natural gas Coal Petroleum
A passerby discovers a dead body by the side of the road. Police investigation reveals blood trails from the street to the location of the body, skid marks on the road prior to the apparent point of impact, and bits of plastic from a car bumper. Can police conclude that this incident was deliberate?
No. The presence of skid marks suggests the driver attempted to avoid collision.
The sun is the most powerful, reliable energy source available on earth. As photovoltaic cells become more efficient, solar power is becoming a more realistic option for supplying our energy needs. Fill in the blanks in the sentences below about photovoltaic cells.
Photovoltaic cells (PVs) convert light energy into electrical energy. PVs are made from semiconductors. Two different types are layered - n-type semiconductors have extra electrons and p-type semiconductors need more electrons. Dopants such as gallium or arsenic are added to allow electrons to flow through the silicon semiconductor. When a photon with enough energy hits the PV, an "extra" electron is "knocked" from one layer into a "hole" in the other. The movement of electrons is an electrical current.
What information can be provided by a forensic autopsy? Select all that apply.
Probable cause of death Presence of toxic substances in the body Length of time since last meal
Identify the element symbol and type the mass number and atomic number using the text boxes and pull-down menu provided below.
Protons: 6 Neutrons: 6
Which is a common characteristic of both nuclear and conventional electric power plants?
Steam Turbines
The use of PCR for DNA amplification employs which enzyme?
Taq polymerase
What is the biggest limitation in the production of petroleum products?
The amount of easily recoverable deposits
which is a known risk associated with nuclear power plants?
The cooling water source can suffer thermal pollution
How is a calorie defined?
The energy needed to increase the temperature of 1 g of water by 1 °C
In what way does the structural formula of a compound differ from its molecular formula?
The structural formula shows the arrangement of atoms and bonds.
Which of the following can be used to determine the heat released by a combustion reaction performed in a calorimeter?
The temperature increase of the calorimeter system
True or false: A computer simulation of a fire can be used to determine the probable cause of a fire.
True
In gas chromatography (GC) _______.
a sample is injected onto a column a substance may be identified by measuring the time it remains on the stationary phase the mobile phase is usually an inert gas
The energy needed to initiate a chemical reaction is called the
activation energy
The diagram below shows a simplified version of a fractionating column used in the petroleum industry. The compounds that are obtained at position D are
asphalt
Biofuels are energy sources that are produced from contemporary ____ matter.
biological
The ______ point of a liquid occurs when the vapor pressure of the liquid equals the external atmospheric pressure, while the ______ point occurs when the vapor pressure of the liquid equals its lower flammability limit.
boiling; flash
Energy is required to ____ (break/form) bonds, whereas energy is released when bonds are ____ (broken/formed).
break; formed
Which of the following is not a drawback of using coal for energy production?
difficult transportation due to instablility
complete the following statement while ignoring any thermodynamic considerations. a candle may be considered a more efficient producer of light than a flashlight because it
converts chemical energy into light
When a molecular substance evaporates (passes from the liquid to the gas phase), the _____ within each molecule remain intact, but the _____ are broken.
covalent bonds; intermolecular attractions
During petroleum refining, catalysts play an extremely important role during the
cracking and reforming processes.
The intermolecular attractions between nonpolar molecules such as hydrocarbons are called London ____ forces.
dispersion
The process by which a solution is heated to its boiling point and the vapors are condensed and collected is known as
distillation
Which of the following are forms of kinetic energy?
electrical energy
The ability to do work or produce change is called
energy
A chemical reaction accompanied by a release of energy is called a/an __________ reaction.
exothermic
An ____ reaction releases energy/heat, whereas an ____ reaction requires energy/heat.
exothermic; endothermic
Converting a substance from liquid to solid states is considered an ____ (exothermic/endothermic) process. The conversion from liquid to gaseous states is considered an ____ (exothermic/endothermic) process.
exothermic; endothermic
he process of burning natural gas is (Click to select) exothermic endothermic because heat is (Click to select) absorbed given off .
exothermic; given off
date, solar radiation is not a practical source for the production of electricity used to power
fleets of taxis.
Isomers have the same _____ but different _____.
formula; structures
Gas chromatography is an analytical technique that separates substances on the basis of their relative _______.
polarity
The higher the heat of combustion of a solvent, the ______ the amount of heat released when the solvent burns in oxygen and the ______ it is to exceed the activation energy of the solvent. This results in a ______ flash point.
greater; easier; lower
A calorimeter is used to measure the ____ released or absorbed by a reaction.
heat
In an exothermic chemical reaction
heat is released as the reaction proceeds
Compounds containing only carbon and hydrogen are called ____.
hydrocarbons
Petroleum (crude oil) is a complex mixture of thousands of substances, the majority of which are
hydrocarbons.
Attractions between individual molecules are called ____ attractions.
intermolecular
The energy of motion is called __________ energy.
kinetic
In which example is the entropy of the initial state greater than the entropy of the final state?
liquid water freezes into ice
A particular gas chromatograph is set up with a nonpolar stationary phase. A nonpolar component injected onto the column will have a ______ retention time than a polar component.
longer
The ease with which a liquid evaporates depends on the strength of its intermolecular forces. A liquid with stronger intermolecular forces will have a ______ vapor pressure at a given temperature and thus a ______ boiling point.
lower; higher
Which of the following is a proper use for a calorimeter?
measuring the heat of combustion
Which is a fossil fuel?
natural gas
Combustion is a chemical process in which a fuel combines with ________ to release energy and form products.
oxygen
which type of renewable energy has most commonly been adapted for use on an individual home basis?
photovoltaic
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
platinum and palladium.
When coal is burned in a power plant, __________ energy is converted into electricity, a form of kinetic energy.
potential
When oil is burned in a power plant, the _____ energy of the oil is converted into heat, which increases the _____ energy of the water.
potential; kinetic
The time taken for a component to flow through the column in gas chromatography and reach the detector is called its ______ time.
retention
Hydrocarbons with only ____ bonds between carbon atoms are called alkanes.
single
Fats are _____ at room temperature, whereas oils are _____ under the same conditions.
solids; liquids
Energy conversion can never be 100% efficient because _____.
some amount of potential energy is always dissipated as heat
A liquid will have a higher boiling point if its intermolecular attractions are ______.
stronger The stronger the intermolecular forces, the less readily the liquid will evaporate and the lower its vapor pressure at a given temperature. This means that the liquid must be heated to a higher temperature in order for its vapor pressure to equal the external pressure.
The property of matter that determines the direction of heat flow is the
temperature.
The bond energy of a C-H bond is _____.
the amount of energy consumed to break a C-H bond
Cracking is
the breaking of larger molecules into smaller ones.
Activation energy is best described as _____.
the energy required to initiate a chemical reaction
The boiling point of a liquid is the temperature at which _______.
the vapor pressure of the liquid equals the external pressure
Success in business today is judged on three criteria, including profitability, fair treatment of employees, and environmental impact. This is known as the ____ bottom line.
triple
A liquid can evaporate at any temperature, producing vapor above the surface of the liquid. This vapor exerts a pressure, which is called the ____ pressure. This pressure ____ as the temperature of the liquid increases. When this pressure equals the external pressure, the liquid has reached its boiling point.
vapor; increases