Chem Exam 1
Which corresponds to the composition of the ion typically formed by fluorine? - (#protons 9)(#electrons 10) (net charge 1+) - (#protons 9)(#electrons 10) (net charge 1-) - (#protons 9)(#electrons 8) (net charge 1-) - (#protons 9)(#electrons 8) (net charge 1+)
(#protons 9)(#electrons 10) (net charge 1-)
The greenhouse and enhanced greenhouse effects refer to the return of approximately ______ percent and greater than ______ percent of the heat radiated by Earth. - 40;40 - 50; 50 - 60; 60 - 80; 80
- 80; 80
Choose the proper coefficients for each substance to balance this equation. ___C2H4 + ___ O2 > ___ CO2 + ___ H2O - 1, 1, 2, 2 - 1, 3, 2, 2 - 2, 3, 4, 2 - 2, 2, 4, 2
1, 3, 2, 2
What is the mass number for an atom of xenon containing 54 protons and 75 neutrons?
129
Determine the number of protons and electrons in Mg²⁺ - 10p, 12e - 12p, 12e - 12p, 10e - 12p, 14e - 10e, 10e
12p, 10e
Balance this equation P4 + Cl2 → PCl5 with the smallest whole number coefficients. Choose the answer that is the sum of the coefficients. (Do not forget coefficients of "one.") - 7 - 9 - 11 - 13 - 15
15
Balance the following chemical equation (if necessary): C₃H₆(g) + O₂(g) → CO₂(g) + H₂O(g)
2 C₃H₆(g) + 9 O₂(g) → 6 CO₂(g) + 6 H₂O(g)
What numbers belong in the blank spaces to fully balance the following reaction? __Fe (s) + __Cl₂ (g) → __FeCl₃ (s)
2, 3, 2
Which of the following would be described as "fine particles?" - SOx - NOx - O3 - 2.5 μm diameter soot
2.5 μm diameter soot
How many bromide ions can combine with one ion of aluminum to form an ionic compound? - 3 - 6 - 1 - 2
3
How many protons (p) and electrons (e) are found in a Se²⁻ ion? - 34 p, 36 e - 34 p, 32 e - 32 p, 34 e - 36 p, 34 e - 34 p, 34 e
34 p, 36 e
What, approximately, is the highest concentration of CO2 measured in the Earth's atmosphere in modern times? - 4000 ppm - 400 ppm - 40 ppm - 4.0 ppm
400 ppm
Determine the number of protons (p) and electrons (e) in N³⁻. - 10p, 7e - 7p, 10e - 7p, 7e - 7p, 9e - 10p, 10e
7p, 10e
Although coal is a complex mixture of substances, its elemental composition can be approximated by the formula C135H96O9NS. Using this chemical formula, calculate the percentage, by mass, of carbon (C) in coal. - 85% - 67% - 56% - 20%
85%
Ozone in our atmosphere is important because it - Absorbs some UV radiation - Helps trees grow - Reacts with excess CO2 - Reflects IR radiation
Absorbs some UV radiation
An inversion layer happens when a certain weather pattern traps cooler air near the surface of the earth with a warmer air mass above it. Why is this a problem? - Excess precipitation could cause flooding - The cold air increases the chance for snowstorms - Heatwaves can occur - Air pollution concentrates in the inversion layer
Air pollution concentrates in the inversion layer
Which is correct? - Ozone forms by combining an oxygen atom with an oxygen molecule - There is a dynamic steady state of ozone in the stratosphere - UV radiation will dissociate ozone into an oxygen atom and an oxygen molecule - All of these choices are correct
All of these choices are correct
The ozone hole is most prominent on the Earth over - North America - Europe - Africa - Antarctica
Antarctica
The greenhouse effect refers to the process by which - atmospheric oxygen and nitrogen absorb heat radiated by Earth. - atmospheric nitrogen absorbs ultraviolet radiation radiated by Earth. - atmospheric gases trap and return infrared radiation radiated by Earth. - greenhouse gases absorb ultraviolet radiation from the Sun, warming the molecules.
Atmospheric gases trap and return infrared radiation radiated by Earth
Scientists have correlated average global temperature with atmospheric carbon dioxide levels for the last 160,000 years using ice cores from Antarctica. How is the carbon dioxide level determined? - By measuring the CO2 concentration in trapped air bubbles in the ice layers - By measuring the 18O/16O ratio in the CO2 molecules - By extrapolating the CO2 level from the temperature of the ice - By extrapolating the CO2 level from the average global temperature
By measuring CO2 concentration in trapped air bubbles in the ice layers
HFCs may be used to replace CFCs. Which compound is a HFC? - CH2Cl—CCl2F - CH2FCl - CF3CH2F - CHClF2
CF3CH2F
All of these pollutants can be detected by their odors except - CO - O3 - SOx - NOx
CO
Which component of the air makes up approximately 100 times more of an exhaled breath than of an inhaled breath? - Ar - O2 - O3 - CO2
CO2
Although carbon dioxide is the primary compound discussed with respect to global warming; of the common atmospheric components the global warming potential (GWP) of a carbon dioxide molecule is very low. Which statement best explains this pair of facts? - CO2 molecules are highly symmetrical - CO2 has a low molar mass - CO2 exists in relatively high concentrations - CO2 is formed in the combustion of fossil fuels
CO2 exists in relatively high concentrations
What is the chemical formula for carbon disulfide? - CH4 - CS2 - C2H6 - H2SO4
CS2
Most of the electricity in the U.S. is produced by converting the energy in fossil fuels to electricity. Fill in the different types of energy along the path of this transformation. __________ v Burner __________ v turbine __________ v generator _________ - kinetic energy - electrical energy - chemical potential energy - mechanical energy
Chemical potential energy v burner Kinetic energy v turbine Mechanical energy v generator Electrical energy
Which product of the ultraviolet decomposition of CFCs acts as the catalyst for ozone decomposition? - Oxygen atoms - Chlorine atoms - Fluorine atoms - Hydrogen atoms
Chlorine atoms
Which contributes to the ozone hole? - Automobile exhaust - Chlorofluorocarbons (CFCs) - Loss of northern forests - All of these choices are correct
Chlorofluorocarbons (CFCs)
Which explanation accounts for the fact that, on average, cloudy nights are warmer than clear nights? - Clouds reflect light incoming from the moon - H2O does not absorb infrared energy - Clouds are composed of water vapor and H2O is a strong greenhouse gas - Clouds have a high concentration of carbon dioxide from fossil fuel combustion
Clouds are composed of water vapor and H2O is a strong greenhouse gas
Which type of material is defined as having a well-ordered atomic structure? - Amorphous - Crystalline - Transparent - Opaque
Crystalline
Identify the single most effective strategy to reduce carbon dioxide emissions. - Use methane rather than gasoline for fuel in cars and trucks - Develop alternate energy sources that do not rely on fossil fuels - Use wood as a home heating fuel - Convert all vehicles to diesel fuel
Develop alternate energy sources that do not rely on fossil fuels.
All processes either require energy or give off energy. Sort the examples by whether they are exothermic or endothermic. - burning candle - the reaction in a chemical "hot pack" for warming hands in winter - photosynthesis -- plants using sunlight to turn CO2 into plant material - the reaction in a chemical "cold pack" for treating injuries - a mammal metabolizing food - water evaporating - setting off a firework - ice melting
Exothermic - A mammal metabolizing food - The reaction in a chemical "hot pack" for warming hands in water - 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
The most abundant greenhouse gas in Earth's atmosphere is - CO2 - H2O vapor - N2 - CH4
H2O vapor
Which is the balanced chemical equation showing hydrogen peroxide (H2O2) decomposing into hydrogen (H2) and oxygen (O2)? - H2O2 → H2 + O2 - H2 + O2 → H2O2 - 2 H2 + O2 → 2 H2O2 - 2 H2O2 → 2 H2 + O2
H2O2 → H2 + O2
Which conclusion was considered "very likely" in the 2014 report of the Intergovernmental Panel on Climate Change? - Human-caused emissions are the main factor causing warming since 1951 - The observed warming of the past 100 years is due solely to climate variability - The Arctic Sea ice thickness decreased approximately 40% during late/early fall - Summer droughts have increased
Human-caused emissions are the main factor causing warming since 1951
Where is most fo the carbon on earth stored? - In the form of fossil fuels and carbonate minerals and rocks - In the forests and soil - In surface water - In the atmosphere
In the form of fossil fuels and carbonate minerals and rocks
Chlorofluorocarbons rise to the stratosphere and - react directly with stratospheric ozone to destroy it - interact with UV energy to produce free radicals that destroy ozone - interact with UV energy to produce free radicals that react with oxygen to create ozone - react with free radicals to remove carbon dioxide
Interact with UV energy to produce free radicals that destroy ozone
Which one of the following compounds is considered to be an ionic compound? - NO - CCl4 - LiF - Pl3
LiF
Which substance is not considered to be an air pollutant? - N2 - SO2 - NO2 - O3
N2
Which is the balanced chemical equation for the reaction of nitrogen (N2) with oxygen (O2) to form NO? - 2 NO → N2 + O2 - N2 + O2 → NO - N2 + O2 → 2 NO - NO → N2 + O2
N2 + O2 → 2 NO
Consider the list of gases shown below. Select those you would expect to find coming directly from a vehicle's tailpipe. Check all that apply - N2 - CO - O3 - NO - CO2 - SO2
N2, CO, NO, CO2
The chemical formula for nitrogen monoxide is - N2O. - NO. - NO2. - N2O3.
NO
In order to halt increases in the amounts of these gases in the Earth's atmosphere, global greenhouse gas emissions must be decreased by 9 billion tons. Which of these would not provide that much relief in global greenhouse gas emissions? - Cutting energy usage in the world's buildings by 20-25 percent below business-as-usual - Having all cars get 60 mpg instead of 30 mpg - Replacing 700 large coal-burning power plants with nuclear, wind, or solar power - Capturing and sequestering carbon dioxide at 800 coal-burning power plants - None of these choices would provide the needed 9 billion tons
None of these choices would provide the needed 9 billion tons
Which component of the air is an element? - H2O - NO2 - O2 - CO2
O2
Which pollutant is present in air as particulate matter? - Soot - Ozone - Sulfur dioxide - carbon monoxide
Soot
Scientists believe they know the average global temperature over the last 160,000 years. Which property of the ice core samples from Antarctica provides this information? - The thickness - The carbon dioxide concentration - The 1H/2H ratio - The temperature
The 1H/2H ratio
Why are HFCs inappropriate for long-term replacement of CFCs? - They are flammable - They are very toxic - They absorb infrared radiation - They are an appropriate replacement
They absorb infrared radiation
The Montreal protocol is a - treaty to protect against global warming - treaty to reduce the amount of CFCs produced in the world - list of substitutes for CFCs - way to destroy CFCs in the stratosphere
Treaty to reduce the amount of CFCs produced in the world
Determine the shape or geometry of PH3. (Hint: Use the Periodic Table to arrive at the electron configuration for phosphorous.) - Tetrahedral - Trigonal pyramid - Bent - Trigonal planar
Trigonal pyramidal
Which country has the highest per capita emission of carbon dioxide? - United States - Germany - Canada - Saudi Arabia
United States
In which one of the following processes is the system endothermic? - a process in which the air around the reaction becomes warmer - a process taking place in solution where the solution temperature decreases - the combustion of natural gas - the formation of frost on a window
a process taking place in solution where the solution temperature decreases
When it reaches its largest size, the ozone hole over the Antarctic is - about as large as North America - about the same size as France - smaller than Iceland - about the same size as Canada
about as large as North America
Which one of the following phase changes would be endothermic? - boiling a liquid - freezing a solid - condensation of a gas into a liquid - condensation of a gas into a solid
boiling a liquid
Which one of the following processes is exothermic? - making coffee - baking a cake - burning wood in a campfire - photosynthesis
burning wood in a campfire
The name of the compound formed by combining carbon atoms with oxygen atoms is - carbon oxide - monocarbon dioxide - carbon dioxide - carbonate
carbon dioxide
Which one of the following is an example of a homogenous mixture? - coffee - salt - concrete - iron
coffee
A substance that can be broken down into two or more simpler substances by chemical methods is called a(n) - compound - mixture - element - isotope
compound
Which one of the following phase changes would be exothermic? - sublimation - vaporization - condensation - melting
condensation
Which one of the following processes is exothermic? - boiling a liquid - condensation of a gas into a liquid - melting a solid - converting solid into gas
condensation of a gas into a liquid
A recent set of advertisements has a picture of an aluminum can with an aluminum-frame bicycle, along with a hypothetical quote from the can that reads: "I want to be a bike.. Recycle me." The analysis of the life cycle of an item starting with its raw materials and ending with the used item becoming the raw material for new products is called - cradle-to-grave - reusability - cradle-to-cradle - cost-benefit analysis
cradle-to-cradle
P2O5 is the chemical formula for - pentoxygen diphosphide - diphosphorus pentoxide - dioxygen pentaphosphide - monophosphorus pentoxide
diphosphorus pentoxide
What term is defined as the flow of electrons from one location to another? - resistance - transparency - density - electricity
electricity
The first law of thermodynamics states that - energy is the capacity to do work - doing work is defined as causing movement against a resisting force - heat flows from a warmer body to a cooler body - energy is neither created nor destroyed
energy is neither created nor destroyed
What are the three pillars of sustainability? - reduce, reuse, recycle - equitability, justice, quality of life - diversity, efficiency, toxicity - environmental, social, economic
environmental, social, economic
A chemical reaction accompanied by a release of energy is called a/an ________ reaction. - endothermic - catalyzed - exothermic - fast
exothermic
Radiative forcings are - geological changes that promote volcanic eruptions. - mechanisms for sequestering CO2 endorsed by signers of the Kyoto Protocol. - factors that influence the balance of Earth's incoming and outgoing radiation. - changes in geographical distribution of plant, animal, and insect species brought on by climate change.
factors that influence the balance of Earth's incoming and outgoing radiation
On a Periodic Table, the columns of elements with similar properties are - periods - groups - rows - metals
groups
Single bonds, double bonds, and triple bonds - have 1, 2, and 3 shared electrons, respectively - have 2, 4, and 6 shared electrons, respectively - have 3, 6, and 9 shared electrons, respectively - are only possible between carbon atoms
have 2, 4, and 6 shared electrons, respectively
How is heat energy used to generate electricity in a modern power plant? - heat warms wires causing electrons to move through them more rapidly - heat boils water to make steam, which drives a turbine - heat warms the fins on a turbine, causing them to spin - heat generates strong magnetic fields through which the wires of a turbine move
heat boils water to make steam, which drives a turbine
In an exothermic chemical reaction - the mass of the products is greater than the mass of the reactants - the mass of the products is less than the mass of the reactants - heat is released as the reaction proceeds - heat is absorbed as the reaction proceeds
heat is released as the reaction proceeds
Which characteristics pertain to the problem of global warming? i. Possible consequences include altered climate and increased sea level. ii. Heat energy radiated by the earth is captured by atmospheric molecules. iii. Increased skin cancer incidence and damage to radiation sensitive species has been observed. iv. The concentration of stratospheric ozone is declining.
i and ii only
Which practices might be described as carbon sequestration? i. Planting trees ii. Deforestation iii. Pumping carbon dioxide deep into the ocean iv. Increasing combustion of fossil fuels
i and iii only
In order to make useful predictions, which factors must be accounted for by climatic models? i. Cooling effect of atmospheric aerosols ii. Smoke, haze, and cloud cover iii. Change in land use iv. Combustion of fossil fuels
i, ii, iii, and iv
Methane is approximately 23 times more powerful than carbon dioxide as a greenhouse gas. Which are significant sources of methane emissions? i. The digestive systems of ruminants (cows, sheep, etc.) ii. Automobile exhaust iii. Rice cultivation iv. Decaying wetland vegetation
i, iii, and iv only
Which occurrences or processes are expected to reduce the level of atmospheric carbon? i. Decaying plant and animal remains ii. The growth of trees iii. Formation of carbonate rock in the ocean iv. Animal respiration
ii and iii only
As the ozone hole gets more pronounced, with time, one expects the incidence of skin cancer to - Decrease worldwide - Increase worldwide - Increase in the northern hemisphere and decrease in the southern hemisphere - Decrease in the northern hemisphere and decrease in the northern hemisphere
increase worldwide
An atom has nine protons and ten electrons. This makes it: - nonstoichiometric - ion - cathode ray - alpha particle - neutrally charged
ion
Land use changes have a big impact on global warming because of their effect on albedo. Albedo - is the primary wave number at which green house gas absorbs infrared radiation - describes the effectiveness of a molecule as a greenhouse gas - is the ratio of electromagnetic radiation reflected by a surface to the amount of radiation hitting that surface - describes the tendency of an atmospheric molecule to react with other atmospheric molecules, reducing their global atmospheric lifetimes
is the ratio of electromagnetic radiation reflected by a surface to the amount of radiation hitting that surface
What is the effect of the absorption of infrared energy on matter? - it excites bonding electrons - it increases molecular rotation - it breaks chemical bonds - it increases the vibration of chemical bonds
it increases the vibration of chemical bonds
Which one of the following is an example of a heterogenous mixture? - apple juice - tap water - air - italian salad dressing
italian salad dressing
The energy of motion is called ___________ energy. - electrical - mechanical - potential - kinetic
kinetic
The most numerous of the elements are the - metals - nonmetals - metalloids - noble gases
metals
Air is a(n) - element - compound - mixture - pure substance
mixture
The carbon cycle refers to the - mechanism by which carbon dioxide causes global warming. - frequency of light energy that affects the rotational energy of carbon dioxide. - oxidation of glucose to form carbon dioxide and water. - movement of carbon through living organisms, the atmosphere, the sea, and the earth.
movement of carbon through living organisms, the atmosphere, the sea, and the earth
Ozone is a secondary pollutant. A secondary pollutant is - not as hazardous as a primary pollutant. - not produced directly but as the product of the interaction of two or more pollutants. - one that is naturally present in our atmosphere. - one that is less hazardous than a primary pollutant.
not produced directly but as the product of the interaction of two or more pollutants.
The atomic number is the - same as the mass number of an atom - number of protons in a nucleus - number of protons and neutrons in a nucleus - number of neutrons in a nucleus
number of protons in a nucleus
Combustion is a chemical process in which a fuel combines with ________ to release energy and form products. - nitrogen - oxygen - methane - hydrogen
oxygen
The energy stored in the chemical bonds of fossil fuels is a form of ____________ energy. - electrical - mechanical - potential - kinetic
potential
The Industrial Revolution is a key point in the Earth's atmospheric history because - prior to that time large deposits of petroleum and coal were not being used as energy sources. - the first atmospheric studies were conducted at that time. - spectrometers that could measure molecular response to infrared radiation were developed at that time. - the first aircraft that could be used to collect atmospheric samples were developed at that time.
prior to that time large deposits of petroleum and coal were not being used as energy sources.
When only one pair of shared electrons is involved in a covalent bond, the linkage is called a ____ bond. - triple - single - double - resonant
single
Green chemistry is - the study of how to improve the production of oxygen via photosynthesis. - any chemistry having an agricultural base. - the cause of the higher temperatures and humidity typically found in greenhouses. - the design of products and processes that reduce hazardous substances.
the design of products and processes that reduce hazardous substances.
The O-to-O-to-O bond angle in an ozone (O3) molecule is not exactly 120° because - ozone molecules are linear so the bond angle is 180°. - ozone molecules are tetrahedral so the bond angle is approximately 109°. - the nonbonding electron pair occupies greater space than the bonding pairs. - the electrons in the double bond occupy more space that the nonbonding electron pair.
the nonbonding electron pair occupies greater space than the bonding pairs
What distinguishes the atoms of one element from another? - the number of neutrons - the number of protons plus neutrons - the number of protons - the number of neutrons plus electrons
the number of protons
Which common process on earth is endothermic? - the production of oxygen by photosynthesis - the combustion of methane - water freezing to form ice at 0 celsius - the reaction of wood with oxygen to form carbon dioxide, water, and ash
the production of oxygen of photosynthesis
In the periodic table, which elements typically have similar properties? - those in the same rows - those related diagonally - those in the same columns - those on opposite sides
those in the same columns
What two factors are considered when determining the risk assessment for air pollutants? - exposure and ppm - percentage and ppm - toxicity and percentage - toxicity and exposure
toxicity and exposure
DNA, the genetic material of living organisms, is damaged by light in the - visible region of the spectrum. - ultraviolet region, especially below a wavelength of 320 nm. - ultraviolet region, especially above a wavelength of 340 nm. - infrared region of the spectrum.
ultraviolet region, especially below a wavelength of 320 nm.
Of five major gaseous components of air, which is the only one to vary significantly in concentration from place to place and from day to day? - water vapor - carbon dioxide - nitrogen - argon
water vapor
