CHEM 108 - Exam 2 Connect Questions
Place the steps for the production of ethanol from corn in order, with the first step at the top of the list. - corn kernels are mixed with water. - yeast fermentation converts sugars into ethanol - the mixture is distilled - enzymes break down starches into glucose
- corn kernels are mixed with water. - enzymes break down starches into glucose - yeast fermentation converts sugars into ethanol - the mixture is distilled
Based on Table 6.2, to break a S-H covalent bond requires _____ kJ/mol of energy.
347 kJ/mol
A sample of fuel is burned in oxygen, producing heat and light. Based on the first law of thermodynamics, which statement must be true? a. The energy lost from the fuel and oxygen is equal to the energy of the heat and light. b. The fuel gained energy by combining with oxygen. c. The energy of the fuel changed from chemical energy to potential energy. d. The amount of energy the oxygen gained is equal to the amount the fuel lost.
A. The energy lost from the fuel and oxygen is equal to the energy of the heat and light.
Match each solar body with the primary type of radiation it emits. Earth: Sun: - infrared radiation - ultraviolet, visible, and infrared radiation
Earth: infrared radiation Sun: ultraviolet, visible, and infrared radiation
Match each reaction type correctly to its description. Exothermic Endothermic - A reaction that absorbs heat - A reaction that releases heat
Exothermic: A reaction that releases heat Endothermic: A reaction that absorbs heat
Match each type of energy to its definition. Potential energy Kinetic energy energy of motion stored energy or energy of position
Potential energy: stored energy or energy of position Kinetic energy: energy of motion
What was the result of the energy balance study on the production and use cycle of biodiesel? a. The study determined that biodiesel efficiency varied dramatically with the source of the fats. b. Biodiesel consumes slightly more energy from fossil fuels than it generates. c. Biodiesel has a net CO2 release comparable to that of most fossil fuels. d. Biodiesel generates over 300% more energy than is required to produce it.
d. Biodiesel generates over 300% more energy than is required to produce it.
Which of the following can be used to determine the heat released by a combustion reaction performed in a calorimeter? a. The mass of fuel that reacts b. The amount of light released during the reaction c. The amount of oxygen consumed d. The temperature increase of the calorimeter system
d. The temperature increase of the calorimeter system
The natural process by which Earth's atmospheric gases trap the infrared radiation radiated by Earth is called the _____ effect. This causes Earth's average surface temperature to be _____ than that predicted when considering the distance of the Earth from the Sun. a. global warming; lower b. global warming; higher c. greenhouse; lower d. greenhouse; higher
d. greenhouse; higher
Fats are _____ at room temperature, whereas oils are _____ under the same conditions. a. solids; gases b. gases; liquids c. liquids; solids d. solids; liquids
d. solids; liquids
the most important greenhouse gas to Earth is carbon _______
dioxide
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.
endothermic, exothermic
The ability to do work or produce change is called _______
energy
The process by which atmospheric gases trap and return more than 80% of the heat energy radiated by Earth is called the ________ greenhouse effect, resulting in an increase in average global temperatures.
enhanced
A gas that is able to absorb and trap infrared radiation, resulting in a warming of the atmosphere, is called a(n) ______ gas.
greenhouse
A calorimeter is used to measure the _____ released or absorbed by a reaction.
heat
One ______ of any substance contains Avogadro's number of particles.
mole (mol)
The molar mass of any substance is the mass of 1 _____ of the particles of that substance
mole, mol, or g/mol
Biofuels are energy sources that are produced from contemporary _____ matter.
plant, biological, living, organic, renewable, or agriculture
Contrast weather and climate by matching each term to the correct definition. Weather: Climate: - Describes events of relatively short duration, including daily high and low temperatures. - Describes regional events recorded over longer periods.
Weather: Describes events of relatively short duration, including daily high and low temperatures. Climate: Describes regional events recorded over longer periods.
Use bond energies (see table) to estimate the heat of combustion of C3H8. a. -2024 kJ/mol b. +320 kJ/mol c. -3784 kJ/mol d. +3784 kJ/mol e. +2024 kJ/mol f. -320 kJ/mol
a. -2024 kJ/mol
How many of each type of bond are formed or broken in the following reaction? (Select all that apply.) 2C≡O (g) + O=O (g) → 2O=C=O (g) a. 1 O=O bond is broken b. 2 C≡O bonds are broken c. 2 C=O bonds are formed d. 4 C=O bonds are formed e. 1 O=O bond is formed f. 2 C≡O bonds are formed
a. 1 O=O bond is broken b. 2 C≡O bonds are broken d. 4 C=O bonds are formed
Which of the following options correctly interpret the information provided by the balanced equation CH4 + 2O2 → CO2 + 2H2O? (Select all that apply.) a. 1 mole of CH4 produces 1 mole of CO2 when reacted with 2 moles of O2. b. 20.00 g of H2O will be produced when 20.00 g of O2 reacts completely with CH4. c. 15 mol of CH4 will produce 15 mol of CO2 when burned completely in O2. d. 1.00 g of CH4 requires 2.00 g of O2 to react completely. e. 1 molecule of CH4 reacts with 2 molecules of O2.
a. 1 mole of CH4 produces 1 mole of CO2 when reacted with 2 moles of O2. c. 15 mol of CH4 will produce 15 mol of CO2 when burned completely in O2. e. 1 molecule of CH4 reacts with 2 molecules of O2.
Which of the following reflects the correct procedure to calculate the molar mass of CH2Cl2? Multiple choice question. a. 12.0 + 2(1.0) + 2(35.5) = 85.0 g/mol b. 12.0 + 2(1.0) + 35.5 = 49.5 g/mol c. 12.0 + 1.0 + 35.5 = 48.5 g/mol d. 2(12.0 + 1.0 + 35.5) = 97.0 g/mol
a. 12.0 + 2(1.0) + 2(35.5) = 85.0 g/mol
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. a. 172 Cal b. 3010 Cal c. 0.332 Cal
a. 172 Cal (720 x .239 = 172 Cal)
In the combustion of methane, how many O-H bonds are formed? Write the balanced equation and consider the Lewis structure of water. a. 4 b. 1 c. 2 d. 3
a. 4
Which of the following options correctly describes a greenhouse gas? a. A gas that absorbs and traps infrared radiation, thus warming the atmosphere b. A gas that transmits ultraviolet radiation more effectively, leading to a higher atmospheric temperature c. A gas that is toxic to Earth's atmosphere d. A gas that blocks the Sun's radiation, causing the Earth to cool
a. A gas that absorbs and traps infrared radiation, thus warming the atmosphere
Which of the following statements correctly describe bond energy? Select all that apply. a. Bond energy values are always positive. b. Bond energy is the energy input required to form a chemical bond. c. The total energy required to break apart a molecule depends on the number and type of bonds. d. All bonds between the same elements have the same bond energy.
a. Bond energy values are always positive. c. The total energy required to break apart a molecule depends on the number and type of bonds
Which of the following are considered exothermic processes? (Select all that apply.) a. Burning a fuel b. Freezing water c. Melting ice d. Boiling water
a. Burning a fuel b. Freezing water
Which statement best defines the first law of thermodynamics? a. Energy can be neither created nor destroyed. b. The amount of energy in the universe is constantly decreasing. c. Some energy is lost whenever it changes form. d. Stored energy can only be released as heat.
a. Energy can be neither created nor destroyed.
Which of the following statements correctly describe the mole? Select all that apply. a. The number of particles in a mole is called Avogadro's number. b. One mole of any substance contains 6.02 x 1023 particles. c. The mole can only be used to describe numbers of atoms. d. The mole is abbreviated mo.
a. The number of particles in a mole is called Avogadro's number. b. One mole of any substance contains 6.02 x 10^23 particles.
Which of these equations gives the net efficiency for an energy transformation in a power plant? a. (heat generated by fuel/electrical energy needed) x 100 b. (electrical energy produced/heat from fuel) x 100 c. (total energy generated/energy converted to electricity) x 100 d. (electrical energy produced/electrical energy consumed) x 100
b. (electrical energy produced/heat from fuel) x 100
The production of nitric acid (HNO3) is closely linked to the manufacture of fertilizers, and it is estimated that 60 million tons of this substance was produced worldwide in 1999. What is the mass of nitrogen in this quantity of nitric acid? a. 30 million tons b. 13 million tons c. 27 million tons d. 270 million tons
b. 13 million tons
Based on Table 6.2, how much energy is required to break a N-Cl covalent bond? a. 272 kJ/mol b. 193 kJ/mol c. 201 kJ/mol d. 160 kJ/mol
b. 193 kJ/mol
Write the balanced equation and draw Lewis structures of reactants and products to determine the number of C=O bonds formed during the combustion of propane. a. 3 b. 6 c. 4 d. 2
b. 6
How can ice-core data provide information about changes in atmospheric CO2 levels over time? a. CO2 dissolved in ice of a particular age can be extracted and analyzed. b. The fossil fuel concentration in the ice cores provides information about the CO2 available in the atmosphere during a given time period. c. Air bubbles trapped in the ice are analyzed to determine the CO2 content at a particular time period.
c. Air bubbles trapped in the ice are analyzed to determine the CO2 content at a particular time period.
Which chlorofluorocarbon has the greatest carbon mass ratio? a. CCl2F2 b. CClF3 c. C2Cl2F4 d. CCl3F
c. C2Cl2F4
Which of the following is an anthropogenic influence on the environment? (Select all that apply.) a. The water cycle b. Erosion c. Cattle farming d. Diamond mining e. Landfills f. Airline transportation
c. Cattle farming d. Diamond mining e. Landfills f. Airline transportation
What are the main economic and social disadvantages of using corn ethanol as a fuel? Select all that apply. a. Using corn for alcohol rather than food has eliminated many jobs and impoverished rural communities. b. The price of ethanol has caused a large decrease in the demand for corn. c. Ethanol is more expensive per volume than crude oil. d. Ethanol production consumes significant fossil fuels to provide energy to plant corn and distill the alcohol.
c. Ethanol is more expensive per volume than crude oil. d. Ethanol production consumes significant fossil fuels to provide energy to plant corn and distill the alcohol.
What is cellulosic ethanol? a. Ethanol produced by chemical means from inorganic materials b. Ethanol produced by combustion of other plant materials instead of fossil fuels c. Ethanol produced from inedible parts of plants
c. Ethanol produced from inedible parts of plants
Which of the following options correctly describe exothermic and endothermic reactions? Select all that apply. a. Endothermic reactions occur more quickly than exothermic reactions. b. The energy change for an exothermic reaction has a positive sign. c. Exothermic reactions produce heat when they occur. d. The energy change for an endothermic reaction has a positive sign.
c. Exothermic reactions produce heat when they occur. d. The energy change for an endothermic reaction has a positive sign.
How can sustainable energy production be achieved using combustible fuel sources? a. More efficient methods of converting heat into electricity must be developed. b. All fossil fuels must be replaced by biofuels. c. It cannot. Combustion must be supplemented by additional renewable energy sources. d. Additional energy could be gained from combustion products, like CO2.
c. It cannot. Combustion must be supplemented by additional renewable energy sources.
What is the modern metric unit of energy? a. British thermal unit (BTU) b. Kilocalorie (kcal) c. Joule (J) d. Watt (W)
c. Joule (J)
Which of the following can be attributed to the atmosphere of planet Earth? a. The Earth is farther from the Sun than Venus. b. The Earth's orbit is larger than expected when considering its distance from the Sun. c. The Earth's average temperature is higher than expected when considering its distance from the Sun. d. The Earth is able to absorb incoming radiation from the Sun.
c. The Earth's average temperature is higher than expected when considering its distance from the Sun.
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? a. 5 hour 25 minutes b. 1 hour 36 minutes c. 45 minutes d. 1 hour 20 minutes
d. 1 hour 20 minutes
Match each compound correctly to its molar mass. CCl4: PF3: SO2: 88.0 g/mol 154.0 g/mol 64.1g/mol
CCl4: 154.0 g/mol PF3: 88.0 g/mol SO2: 64.1 g/mol
Energy is the ability to _____ or to produce _____
work, change
Match each process correctly with the associated energy change. Bond breaking Bond forming - releases energy - absorbs energy
Bond breaking: absorbs energy Bond forming: releases energy
What are the environmental and ethical impacts of increased corn ethanol production? Select all that apply. a. Farmland is being diverted from food to produce ethanol, driving worldwide food prices up. b. Distillation of corn alcohol produces environmentally damaging gases and residue. c. Fertilizers and insecticides used in corn growing have been increasingly introduced to the soil and water. d. The demand for additional farmland has increased the danger of deforestation.
a. Farmland is being diverted from food to produce ethanol, driving worldwide food prices up. c. Fertilizers and insecticides used in corn growing have been increasingly introduced to the soil and water. d. The demand for additional farmland has increased the danger of deforestation.
What is the difference between the terms global warming and climate change? a. Global warming is one aspect of climate change. b. Global warming is a global phenomena and climate change is local. c. Global warming refers to the long-term changes while climate change refers to short-duration weather changes. d. Global warming is a theory and climate change is a fact.
a. Global warming is one aspect of climate change.
Which of the following options correctly describe how the chemical structure of a fuel impacts its heat of combustion? (Select all that apply.) a. Hydrocarbons produce more energy per gram than alcohols or sugars, which contain greater number of oxygen atoms in their structure. b. As the number of hydrogen atoms per carbon atom decreases so does the heat of combustion. c. Sugars are the best producers of energy compared to hydrocarbons or alcohols. d. Heat of combustion increases as the number of oxygen atoms per carbon atom increases.
a. Hydrocarbons produce more energy per gram than alcohols or sugars, which contain greater number of oxygen atoms in their structure. b. As the number of hydrogen atoms per carbon atom decreases so does the heat of combustion.
During an energy conversion, what happens to the energy that is "lost"? a. It becomes kinetic energy of random motion of the surrounding molecules. b. It becomes potential energy stored in chemical bonds. c. It becomes potential energy stored in the positions of the atoms and molecules in an object. d. It becomes kinetic energy of mechanical parts moving and rotating.
a. It becomes kinetic energy of random motion of the surrounding molecules.
Which of the following options correctly describes an exothermic reaction? a. It releases more energy by forming product bonds than is needed to break reactant bonds. b. It releases more energy by breaking reactant bonds than is needed to form product bonds. c. It releases less energy by breaking reactant bonds than is needed to form product bonds. d. It releases less energy by forming product bonds than is needed to break reactant bonds.
a. It releases more energy by forming product bonds than is needed to break reactant bonds.
Which of the following is NOT a greenhouse gas? a. N2 b. N2O c. NO d. O3
a. N2
In order to convert a triglyceride into biodiesel, the compound must be heated with ______ and ______. a. NaOH b. other hydrocarbons c. an alcohol d. CO2
a. NaOH c. an alcohol
What changes are required to reach sustainable energy production? Select all that apply. a. Nonrenewable fuel sources must be replaced by renewable ones. b. Higher standards of living must be reached to limit the energy use of low HDI nations. c. Additional energy sources must be found to meet increasing demand. d. Clean coal and similar technologies must be used to extend the lifetime of fossil fuels.
a. Nonrenewable fuel sources must be replaced by renewable ones. c. Additional energy sources must be found to meet increasing demand.
Which of the following options correctly describe fats and oils? Select all that apply. a. Oils are typically found in plants rather than from animal sources. b. Both fats and oils are triglycerides. c. Oils occur naturally, while fats are synthetic. d. Fats are pure hydrocarbons, while oils contain other atoms in their structure.
a. Oils are typically found in plants rather than from animal sources. b. Both fats and oils are triglycerides.
Which of the following are considered possible effects of climate change? a. Rise in sea levels b. Less extreme precipitation events throughout the world c. An increase in the incidence of insect-borne diseases d. Changes in freshwater distribution e. A global mean surface temperature increase of 5 ∘C or higher
a. Rise in sea levels c. An increase in the incidence of insect-borne diseases d. Changes in freshwater distribution
Which of the following are advantages of biodiesel fuels? Select all that apply. a. The cost of biodiesel production is competitive with the cost of petroleum-based diesel. b. Biodiesel does not require the use of fossil fuels to produce. c. The by-product of biodiesel production, glycerol, is commercially useful. d. Biodiesel produces a much higher energy gain than ethanol.
a. The cost of biodiesel production is competitive with the cost of petroleum-based diesel. c. The by-product of biodiesel production, glycerol, is commercially useful. d. Biodiesel produces a much higher energy gain than ethanol.
How is a calorie defined? a. The energy needed to increase the temperature of 1g of water by 1°C b. The energy needed to lift 1 kg to a height of 1 m c. 1/2000th of the energy expended by an average person in one day d. The energy released when 1 g of a typical fuel is burned
a. The energy needed to increase the temperature of 1g of water by 1°C
Which of the following are forms of potential energy? Select all that apply. a. The energy of an object suspended above the ground b. The energy of a bullet after being fired from a gun c. The energy stored in the chemical bonds of a compound d. The energy of a car driving down the road
a. The energy of an object suspended above the ground c. The energy stored in the chemical bonds of a compound
Which of the following options correctly interpret the information given? (Select all that apply.) Molar mass of SO2 = 64.1 g/mol; atomic mass of sulfur = 32.1 g; atomic mass of oxygen = 16.0 g. a. The mass ratio of sulfur in SO2 is equal to 0.501. b. The percentage oxygen in SO2 is equal to 32.0/64.1 x 100. c. There are 16.0 g of oxygen in every 64.1 g of SO2. d. There are 32.1 g of sulfur in every 64.1 g of SO2.
a. The mass ratio of sulfur in SO2 is equal to 0.501. b. The percentage oxygen in SO2 is equal to 32.0/64.1 x 100. d. There are 32.1 g of sulfur in every 64.1 g of SO2.
How much sulfur dioxide (SO2) can be produced by the combustion of 21 tons of sulfur (S)? a. 21 x 32.0/64.0 = 10.5 tons b. 21 tons/64.0 = 0.33 tons c. 21 tons x 64.0/32.0 = 42 tons d. 21 tons x 64.0 x 32.0 = 43,000 tons
c. 21 tons x 64.0/32.0 = 42 tons
Which of the following options correctly interpret the information given? Select all that apply. Molar mass of NO2 = 46.0 g/mol; molar mass of nitrogen = 14.0 g/mol; molar mass of oxygen = 16.0 g/mol. a. The percentage of nitrogen in NO2 is equal to 30.4%. b. There are 14.0 g of nitrogen in every 46.0 g of NO2. c. There are 16.0 g of oxygen in every 46.0 g of NO2. d. The percentage oxygen in NO2 is equal to 32.0/46.0 x 100%.
a. The percentage of nitrogen in NO2 is equal to 30.4%. b. There are 14.0 g of nitrogen in every 46.0 g of NO2. d. The percentage oxygen in NO2 is equal to 32.0/46.0 x 100%.
Which of the following options correctly describe the enhanced greenhouse effect? Select all that apply. a. This effect has resulted in an increase in average global temperatures on Earth. b. Atmospheric gases trap and return more than 80% of the heat radiated by Earth. c. This effect is essential to make Earth a habitable planet. d. The enhanced greenhouse effect is related to a decrease in the presence of greenhouse gases in the atmosphere.
a. This effect has resulted in an increase in average global temperatures on Earth. b. Atmospheric gases trap and return more than 80% of the heat radiated by Earth.
Which of the following options correctly differentiate between weather and climate? Select all that apply. a. Weather includes daily variations in temperature and rainfall at a single location. b. The climate varies frequently and is subject to constant fluctuation. c. The term "climate" refers to regional trends in temperatures, rainfall, etc. d. The term "weather" refers to events that have a relatively short duration.
a. Weather includes daily variations in temperature and rainfall at a single location. c. The term "climate" refers to regional trends in temperatures, rainfall, etc. d. The term "weather" refers to events that have a relatively short duration.
In chemistry, the mole _______. Select all that apply. a. is abbreviated mol b. is an abbreviation for molecule c. is abbreviated m d. indicates amount of substance
a. is abbreviated mol d. indicates amount of substance
Chemists use the _____ as a unit of amount of substance. a. mole b. kilogram c. gram d. liter
a. mole
Glycerol is a by-product of biodiesel synthesis and is a common component in ______. a. soaps b. drug formulations c. jet fuels d. natural gas e. cosmetics
a. soaps b. drug formulations e. cosmetics
Energy conversion can never be 100% efficient because _____. a. some amount of potential energy is always dissipated as heat b. conversion technology is much more advanced for some forms of energy than others c. it is impossible to extract all the energy from a fuel source d. some energy is destroyed whenever it changes form
a. some amount of potential energy is always dissipated as heat
The net efficiency of the energy transformation in a power plant is best described as _____. a. the ratio of electrical energy produced to the energy supplied by the fuel b. the amount of electrical energy that the plant can produce in a given time c. the total amount of energy that can be extracted from the fuel d. the percentage of the total energy produced that must be used in a given time
a. the ratio of electrical energy produced to the energy supplied by the fuel
Carbon reservoirs _______. (Select all that apply.) a. usually contain carbon in the form of one of its compounds b. exclude atmospheric CO2 c. isolate carbon from the carbon cycle d. exchange forms of carbon with each other e. usually contain carbon in its pure elemental form
a. usually contain carbon in the form of one of its compounds d. exchange forms of carbon with each other
Which of the following options correctly describe the greenhouse effect? Select all that apply. a. Atmospheric gases on Earth transmit more of the Sun's radiation, causing the planet to be warmer than expected. b. Atmospheric gases on Earth trap about 80% of the infrared radiation produced by the Earth, warming the planet. c. The greenhouse effect is a natural process. d. The greenhouse effect causes the average temperature on Earth to be higher than predicted when considering its distance from the Sun.
b. Atmospheric gases on Earth trap about 80% of the infrared radiation produced by the Earth, warming the planet. c. The greenhouse effect is a natural process. d. The greenhouse effect causes the average temperature on Earth to be higher than predicted when considering its distance from the Sun.
Which greenhouse gas listed has the highest molar mass? a. N2O b. CF2Cl2 c. CO2 d. O3
b. CF2Cl2
Which of the following fuels would have the largest heat of combustion, in units of kJ/g? a. C3H8O b. CH4 c. C3H8 d. C2H6O
b. CH4 Explanation: As the amount of O in the fuel increase, the heat of combustion decreases. The H:C ratio for C3H8 is 2.7, which is less than CH4 (4.0). As the H:C decreases, the heat of combustion decreases.
Which carbon and oxygen containing compound has a molar mass of 44.01 g? a. C3O2 b. CO2 c. C2O2 d. CO
b. CO2
Which gas is central to the discussion of global climate change? a. O3 b. CO2 c. N2 d. NO e. O2
b. CO2
Which of the following processes release CO2 into the atmosphere? Select all that apply. a. Photosynthesis b. Combustion c. Respiration d. Decomposition e. Formation of carbonate minerals
b. Combustion c. Respiration d. Decomposition
Which of the following are biofuels? Select all that apply. a. Petroleum b. Ethanol c. Natural gas d. Wood
b. Ethanol d. Wood
True or false: Energy is required to form bonds. a. True b. False
b. False
Which statement about ice cores is correct? a. The deepest layers are the youngest layers. b. The deepest layers are the oldest layers.
b. The deepest layers are the oldest layers.
Which of the following statements correctly describe the carbon cycle? Select all that apply. a. CO2 is found in surface waters on Earth, but not in the deep ocean. b. The main atmospheric form of carbon is CO2. c. Carbon is cycled only between the atmosphere and the oceans. d. CO2 is generated by the combustion of fossil fuels. e. CO2 is generated during the process of photosynthesis.
b. The main atmospheric form of carbon is CO2. d. CO2 is generated by the combustion of fossil fuels.
Which of the following options explain why the term "global warming" is considered inaccurate by some scientists? Select all that apply. a. Global warming is a phenomenon that has been occurring for millions of years. b. The term "global warming" could be thought to describe a benign influence. c. On average the Earth's temperatures have not really increased over time. d. The effects of global warming vary across the globe.
b. The term "global warming" could be thought to describe a benign influence. d. The effects of global warming vary across the globe.
To convert a fat or an oil into biodiesel, the compound is generally heated with an alcohol and a catalytic amount of NaOH. What change results from this process? a. All C=C double bonds are removed from their structure, making them easier to burn. b. The triglyceride is broken into smaller pieces that evaporate more readily. c. All oxygen is removed from its structure, leaving a hydrocarbon fuel.
b. The triglyceride is broken into smaller pieces that evaporate more readily.
Gasohol is ______. a. a blend of natural gas and ethanol b. a blend of gasoline and ethanol c. a mixture of biodiesel and ethanol d. pure ethanol used in car engines
b. a blend of gasoline and ethanol
Both Venus and Earth have higher average surface temperatures than expected because _____. a. both planets trap all the incoming radiation of the Sun b. both planets have atmospheres that trap radiation c. both planets are very close to the Sun
b. both planets have atmospheres that trap radiation
Natural locations that store carbon, usually in the form of one of its compounds, and that naturally exchange carbon with each other are known as ______. a. carbon mines b. carbon reservoirs c. carbon drains d. carbon loops
b. carbon reservoirs
Which of these units are commonly used to express heats of combustion? Select all that apply. a. J/°C b. kcal/g c. kJ/mol d. °C/kg
b. kcal/g c. kJ/mol
The wavelength of radiation that the Earth re-emits is _____ the radiation it absorbs. a. the same wavelength as b. longer than c. shorter than
b. longer than
Which of the following are common greenhouse gases? Select all that apply. a. O2 b. methane (CH4) c. H2O d. CO2 e. Cl2
b. methane (CH4) c. H2O d. CO2
The heat of combustion of a compound is best described as _____. a. the heat that must be supplied to begin combustion of a substance b. the amount of heat released when a specific amount of a substance burns c. the total energy contained in the bonds that make up a substance
b. the amount of heat released when a specific amount of a substance burns
Energy is required to _____ (break/form) bonds, whereas energy is released when bonds are _____ (broken/formed) .
break, formed
Which of the following options correctly describe the changes observed in global temperature over time? Select all that apply. a. The changes in average global temperature do not correspond to the changes in atmospheric CO2 levels. b. Actual global temperatures have fluctuated over time, but the average global temperature has remained relatively constant. c. The average global temperature of the Earth has increased over the past century. d. The average global temperature has increased over the same period as atmospheric CO2 levels have increased.
c. The average global temperature of the Earth has increased over the past century. d. The average global temperature has increased over the same period as atmospheric CO2 levels have increased.
Which of the following statements correctly describe molar mass? Select all that apply. a. The term "molar mass" can be applied to atoms or molecules, but not other particles. b. The term "molar mass" applies to compounds but not to elements. c. The periodic table can be used to calculate the molar mass of any substance. d. The molar mass of oxygen is 16.00 g/mol. This means that 1 mole of oxygen atoms has a mass of 16.00 g. e. The molar mass of a molecular substance is the mass per mole of its molecules.
c. The periodic table can be used to calculate the molar mass of any substance. d. The molar mass of oxygen is 16.00 g/mol. This means that 1 mole of oxygen atoms has a mass of 16.00 g. e. The molar mass of a molecular substance is the mass per mole of its molecules.
Influences on the environment resulting from human activities are called _____ influences. a. anthropomorphic b. sociological c. anthropogenic d. anthropological
c. anthropogenic
Small changes in the average global temperatures are expected to have a(n) _______ impact on our climate. a. small b. insignificant c. huge
c. huge
A particular blend of gasohol is designated E15. This means that ______. a. it has the same burn rate as gasoline containing 15% of iso-octane b. it contains 15% gasoline and 85% ethanol c. it contains 15% ethanol and 85% gasoline d. it produces 15% more energy than pure gasoline
c. it contains 15% ethanol and 85% gasoline
Consider the balanced equation 2H2 + O2 → 2H2O. The coefficients (numbers in front of the formulas) correspond to the number of particles of each substance involved in the reaction, which is proportional to the _____ of each substance. a. atomic mass b. mass in grams c. number of moles
c. number of moles
The bond energy of a C-H bond is _____. a. the amount of energy stored in one molecule of CH b. the amount of energy released by combustion of CH c. the amount of energy consumed to break a C-H bond d. the amount of energy consumed to form a C-H bond.
c. the amount of energy consumed to break a C-H bond
Ice core data shows that atmospheric CO2 levels _____. a. have decreased steadily since the beginning of the last millennium b. have remained fairly constant since the formation of the planet c. were relatively constant from the beginning of the last millennium until around 1800 d. have increased steadily since the formation of the planet
c. were relatively constant from the beginning of the last millennium until around 1800
