Deck 4: Energy From Combustion

Question 1

The heat of combustion of ethane,C₂H₆,is 1560 kJ/mol.What is the heat of combustion of ethane,in kJ per gram?

A)51.9 kJ/g
B)195 kJ/g
C)4.69 × 10⁴ kJ/g
D)9.39 × 10²⁶ kJ/g

Answer 1

51.9 kJ/g

Question 2

The energy of motion is called _________ energy.

A)electrical
B)mechanical
C)potential
D)kinetic

Answer 2

kinetic

Question 3

The first law of thermodynamics states that

A)energy is the capacity to do work.
B)doing work is defined as causing movement against a resisting force.
C)heat flows from a warmer body to a cooler body.
D)energy is neither created nor destroyeD.

Answer 3

energy is neither created nor destroyeD.

Question 4

The energy needed to initiate a chemical reaction is called the

A)heat of combustion.
B)bond energy.
C)activation energy.
D)renewable energy.

Question 5

The energy stored in the chemical bonds of fossil fuels is a form of ______ energy.

A)electrical
B)mechanical
C)potential
D)kinetic

Question 6

In an exothermic chemical reaction

A)the mass of the products is greater than the mass of the reactants.
B)the mass of the products is less than the mass of the reactants.
C)heat is released as the reaction proceeds.
D)heat is absorbed as the reaction proceeds.

Question 7

The conclusion that it is impossible to completely convert heat into work without making other changes in the universe is

A)based on erroneous observations.
B)the concept that increasing entropy characterizes all changes in the universe.
C)another way of stating that all energy is either thermal energy or heat.
D)the second law of thermodynamics.

Question 8

A calorie is defined as exactly 4.184 J.Therefore 1.000 Cal is exactly

A)41.84 J.
B)418.4 J.
C)1000 J.
D)4184 J.

Question 9

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?

A)0.32 kJ
B)3.12 kJ
C)601 kJ
D)804 kJ

Question 10

In which example is the entropy of the initial state greater than the entropy of the final state?

A)A building collapses during an earthquake.
B)A lump of sugar dissolves in a cup of warm water.
C)Liquid water freezes into ice.
D)Liquid water evaporates.

Question 11

How is heat energy used to generate electricity in a modern power plant?

A)Heat warms wires causing electrons to move through them more rapidly.
B)Heat boils water to make steam,which drives a turbine.
C)Heat warms the fins on a turbine,causing them to spin.
D)Heat generates strong magnetic fields through which the wires of a turbine move.

Question 12

In a typical power plant,the combustion of a fuel is used to boil water.The steam then causes a turbine to spin.At this stage,the potential energy of the fuel has been transformed into _________ energy of the spinning turbine.

A)kinetic
B)mechanical
C)electrical
D)potential

Question 13

Based on this reaction and its energy profile,
CH₄(g)+ 2O₂(g)→ CO₂(g)+ 2H₂O(g)
The reaction

A)is exothermic.
B)is endothermic.
C)has a high activation energy.
D)violates the first law of thermodynamics.

Question 14

The energy that flows from a warmer body to a colder body is called

A)heat.
B)temperature.
C)potential.
D)work.

Question 15

Assume that an extremely inefficient electrical utility company delivers electrical energy to your home from a natural gas-burning power plant with an overall efficiency of only 21% and your furnace is 100% efficient in converting electrical energy into heat energy.What mass of natural gas must be burned by the power plant if heating your home requires 3.5 × 10⁷ kJ? The heat of combustion of natural gas is 50.1 kJ/g.

A)1.5 × 10⁵ g
B)3.3 × 10⁶ g
C)3.7 × 10⁸ g
D)8.4 × 10⁹ g

Question 16

The energy equivalent of a certain cheeseburger is approximately 525 Cal.Since 1 Cal is 4.184 kJ this corresponds to

A)1.25 kJ.
B)125 kJ.
C)220 kJ.
D)2200 kJ.

Question 17

Any chemical or physical change that absorbs energy

A)has high activation energy.
B)is an endothermic process.
C)is an exothermic process.
D)is a catalyzed process.

Question 18

The property of matter that determines the direction of heat flow is the

A)mass.
B)temperature.
C)volume.
D)density.

Question 19

A chemical reaction accompanied by a release of energy is called a/an ______ reaction.

A)endothermic
B)catalyzed
C)exothermic
D)fast

Question 20

The measure of how much energy is dispersed in a given process is called the

A)entropy.
B)activation energy.
C)heat of combustion.
D)potential energy.

Question 21

During petroleum refining,catalysts play an extremely important role during the

A)cracking and reforming processes.
B)environmental cleanup of oil wells.
C)extraction of the oil from the earth.
D)physical separation of the various components of the petroleum.

Question 22

Which is produced in the greatest amount from a barrel of petroleum?

A)asphalt and road oil
B)gasoline
C)home heating oil
D)lubricants and waxes

Question 23

Which is a correct statement of the second law of thermodynamics?

A)Entropy of the universe is constantly increasing.
B)Nature allows the conversion of potential energy into kinetic energy,but not vice versa.
C)Heat is the only form of energy that can be converted into work with 100% efficiency.
D)Energy cannot be created or destroyed,but it can change form.

Question 24

The heat energy released or absorbed by a chemical reaction is generally determined by the difference between the energy that

A)must be put in to break the bonds in the reactants and the energy that must be put in to make the bonds in the products.
B)must be put in to break the bonds in the reactants and the energy that is released upon making the bonds in the products.
C)is released upon breaking the bonds in the reactants and the energy that must be put in to make the bonds in the products.
D)is released upon breaking the bonds in the reactants and the energy that is released upon making the bonds in the products.

Question 25

Combustion is a chemical process in which a fuel combines with______ to release energy and form products.

A)nitrogen
B)oxygen
C)methane
D)hydrogen

Question 26

Which common process on earth is endothermic?

A)the production of oxygen by photosynthesis
B)ozone decomposing into O₂ in the upper atmosphere
C)water freezing to form ice at 0°C
D)the reaction of wood with oxygen to form carbon dioxide,water,and ash

Question 27

Which is not a known advantage of natural gas over other fossil fuels?

A)It burns more completely than other fossil fuels.
B)It burns more cleanly than other fossil fuels.
C)It is far more abundant than any other fossil fuel.
D)Sulfur dioxide is rarely produced by burning natural gas.

Question 28

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)Carbon makes up a smaller proportion of coal than it does of petroleum.
C)Coal reserves in the United States are far greater than petroleum reserves.
D)Coal is the source of many more different fuels with a wide range of properties than is petroleum.

Question 29

According to the graph below,
The domestic production of petroleum has steadily decreased since

A)1950.
B)1960.
C)1975.
D)1985.

Question 30

Petroleum (crude oil)is a complex mixture of thousands of substances,the majority of which are

A)carbohydrates.
B)hydrocarbons.
C)natural gases.
D)proteins.

Question 31

According to the graph below,
The net import of petroleum drastically decreased during the years

A)1970 to 1977.
B)1973 to 1975.
C)1977 to 1982.
D)1985 to 1990.

Question 32

Which factor did not play a major role in the formation of fossil fuels from plant matter?

A)high temperatures
B)high pressures
C)an absence of O₂
D)an abundance of sunlight

Question 33

In the petroleum industry,what does a refinery do?

A)It separates crude oil into fractions consisting of compounds with similar boiling points.
B)It separates crude oil from the coal with which it is almost always found.
C)It mixes natural gas or coal with crude oil in order to remove the impurities from the crude oil.
D)It produces the machinery by which crude oil is removed from the grounD.

Question 34

Soft lignite (brown coal)is the lowest grade of coal.Since it has undergone the least change since burial,its chemical composition-and hence its heat of combustion-is most similar to that of

A)natural gas.
B)petroleum.
C)water.
D)wooD.

Question 35

Which is a fossil fuel?

A)wood
B)uranium
C)ethanol
D)natural gas

Question 36

The process by which a solution is heated to its boiling point and the vapors are condensed and collected is known as

A)combustion.
B)cracking.
C)crystallization.
D)distillation.

Question 37

The diagram below shows a simplified version of a fractionating column used in the petroleum industry.
The compounds with the lowest boiling points are condensed at position

A)A
B)B
C)C
D)D

Question 38

According to the graph below,
The major source of energy in the United States during the years 1900 to 1950 was

A)coal.
B)wood.
C)natural gas.
D)petroleum.

Question 39

In which example is the entropy of the initial state lower than the entropy of the final state?

A)A pot of water boils to produce water vapor at 100°C.
B)Librarians put library books back onto the shelves at the end of the day.
C)A raw egg heated at 100°C in boiling water becomes hard boiled.
D)Soldiers are called to attention when the general enters the room.

Question 40

In the year 2000,which two energy sources contributed almost equally to our total energy usage?

A)coal and natural gas
B)petroleum and natural gas
C)petroleum and nuclear electric power
D)coal and nuclear electric power

Question 41

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)obtaining alternative fuels from renewable sources such as garbage
B)reintroducing the use of tetraethyl lead to increase the octane rating of gasoline
C)converting coal into gaseous and liquid fuels similar to petroleum products
D)increasing the use of farm product biomass,such as corn,to produce ethanol.

Question 42

Based on this graph,which group of economies is predicted to have the largest energy consumption in 2010?

A)mature market economies
B)emerging economies
C)transitional economies
D)impossible to say

Question 43

Which is not true about energy conservation within the United States?

A)Over the past two decades,industrial production has increased substantially,whereas the associated energy consumption has gone down.
B)Reusing aluminum saves approximately 70% of the energy required to extract equivalent amounts of aluminum from its ore.
C)Because of conservation efforts and lighter automobiles,gasoline consumption in the United States declined by 50% between the mid-1970s and the early 1990s.
D)By following strict conservation efforts,the United States could eliminate its dependence on imported fossil fuels within a decade.

Question 44

Consider these three compounds.
Which are isomers?

A)I and II only
B)II and III only
C)I and III only
D)I,II,and III

Question 45

In a refinery,the components of petroleum are separated by

A)combustion reactions.
B)crystallization.
C)fractional distillation.
D)isomerization.

Question 46

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)biological enzymes.
B)gold and titanium.
C)platinum and palladium.
D)ultraviolet radiation.

Question 47

Advertising claims sometimes state that adding something mechanical to a car's engine will allow it to recover 100% of the energy that comes from burning gasoline.You should be skeptical of such claims because they violate the

A)first law of thermodynamics.
B)second law of thermodynamics.
C)law of conservation of matter.
D)activation energy requirements of all chemical reactions.

Question 48

Calculate the amount of energy that is saved by replacing a 75-watt incandescent light bulb with an 18-watt fluorescent bulb during the 1500-hour life of the incandescent bulb.One watt is the equivalent of one joule of energy used per second.

A)308,000 kJ
B)405,000 kJ
C)97,200 kJ
D)27 kJ

Question 49

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

A)asphalt.
B)gasoline.
C)jet fuel.
D)refinery gases.

Question 50

Cracking is

A)the breaking of larger molecules into smaller ones.
B)the combination of small molecules to form larger molecules.
C)any reaction that is accompanied by the release of heat.
D)any reaction that is accompanied by the absorption of heat.

Question 51

A gasoline's octane rating is determined by

A)comparing its burning properties to those of pure isooctane,which has an octane rating of 100.
B)comparing its burning properties to those of natural gas,which produces far fewer pollutants than gasoline normally does.
C)comparing the deposits left on the engine cylinders by burning gasoline to the deposits left by burning diesel fuel.
D)comparing the acceleration of a vehicle when burning gasoline to its acceleration when burning pure ethanol.

Question 52

Consider these three compounds.
Which are isomers?

A)I and II only
B)I and III only
C)II and III only
D)I,II,and III

Question 53

A gasoline's octane rating is a measure of the

A)gasoline's resistance to causing knocking in a vehicle's engine.
B)pollutants produced by burning the gasoline in a vehicle's engine.
C)energy content of the gasoline.
D)purity of the gasoline.

Question 54

Over the very long run,the energy source that has the greatest potential to meet humanity's needs is

A)coal.
B)hydropower.
C)renewable biomass.
D)solar (the sun).

Question 55

Compounds with the same molecular formulas but different molecular structures are called

A)isotopes.
B)isomers.
C)isobars.
D)allotropes.

Question 56

Oxygenated gasolines are blends of petroleum-derived compounds with oxygen-containing compounds.Which of the following oxygenated compounds has been discontinued in some states because of potential health risks?

A)ethanol
B)methanol
C)MTBE
D)methane

Question 57

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.

A)A
B)B
C)C
D)D

Question 58

Assume that an extremely inefficient electrical utility company delivers electrical energy to your home from a natural gas-burning power plant with an overall efficiency of only 31% and your furnace is 85% efficient in converting electrical energy into heat energy.What mass of natural gas the power plant must burn if heating your home requires 3.5 × 10⁷ kJ? The heat of combustion of natural gas is 50.1 kJ/g.

A)2650 kg
B)8550 kg
C)2250 kg
D)10,100 kg

Question 59

The general term for plant matter such as trees,grasses,agricultural crops,or other biological material is

A)biomass.
B)cornstarch.
C)diesel.
D)fossil fuel.

Question 60

Which of these statements about biodiesel is not true?

A)Biodiesel is made from renewable resources such as vegetable oils and animal fats.
B)Biodiesel is non-toxic and biodegradable.
C)Biodiesel can be used in diesel engines without major modifications.
D)Biodiesel has been withdrawn from several states due to health concerns.

Question 61

Which of the following has the highest boiling point?

A)Propane
B)Octane
C)Methane
D)Butane

Question 62

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?

A)54 minutes
B)18 minutes
C)1.21 hours
D)You can't tell

Question 63

Which of the following is NOT a drawback of using coal for energy production?

A)Mountaintop mining
B)Mercury in fly ash
C)Mining explosions
D)Difficult transportation due to instability

Question 64

Power plants generate electricity by harnessing the energy stored in chemical bonds.Which lists,in the correct order,the forms that the energy takes to get from a fossil fuel to an electrical outlet?

A)electrical energy → heat energy → mechanical energy → potential energy
B)potential energy → mechanical energy → electrical energy → heat energy
C)electrical energy → mechanical energy → heat energy → potential energy
D)potential energy → heat energy → electrical energy → mechanical energy

Question 65

Which of the following is not a "clean coal" technology already in use?

A)"Coal washing" to remove sulfur and other mineral impurities from the coal before it is burned.
B)"Gasification" to convert coal to a mixture of carbon monoxide and hydrogen.The resulting gas burns at a lower temperature,thus reducing the generation of nitrogen oxides.
C)"Wet scrubbing" to chemically remove SO₂ before it goes up the smokestack.This is accomplished by reacting the SO₂ with a mixture of ground limestone and water.
D)"Sequestration" to capture and store CO₂ before it is emitted into the atmosphere.

Question 66

In what year was the last oil refinery built in the US?

A)1955
B)1985
C)2005
D)1976

Question 67

Which of the following is a proper use for a calorimeter?

A)Measuring heat of combustion
B)Measuring temperature of a mixture
C)Measuring the amount of oxygen consumed in a combustion reaction
D)Measuring entropy of a reaction

Question 68

Which of the following in NOT a step in fractional distillation of crude oil?

A)The crude oil is pumped into a large vessel and heated.
B)As the temperature increases,the compounds vaporize.
C)Fractions are mixed with natural gas to enrich the hydrocarbon content.
D)Once in the gas phase,compounds travel up the tall distillation or fractionation tower.The compounds with smaller molar masses travel higher;the compounds with larger molar masses travel shorter distances up the column

Question 69

Why is the mileage a vehicle gets less when burning E85 than 100% gasoline?

A)It is not,they are the same.
B)It is not,E85 gives better mileage per gallon burned.
C)Ethanol has a lower heat of combustion.
D)Ethanol has a higher heat of combustion.