CHEM 100 Exam 1

The numbers 1 through 4 are used to identify four different elements on the periodic table. Which element is expected to have 2+ charge when it forms an ion? a) 1 b) 2 c) 3 d) 4

a) 1 (it's in the second column)

Calculate the mass of CO2 produced by the combustion of a tank of gasoline. Assume the mass of gasoline is 46.0 kg and that gasoline is pure octane (C8H18). a) 142 kg b) 17.8 kg c) 32.3 kg d) 46.0 kg

a) 142 kg

Which is the balanced chemical equation showing hydrogen peroxide (H2O2) decomposing into hydrogen (H2) and oxygen (O2)? a) H2O2--> H2+O2 b) H2+O2 --> H2O2 c) 2H2+O2--> 2H2O2 d) 2H2O2--> 2H2+O2

a) H2O2--> H2+O2

What is the primary component of an exhaled breath? a) N2 b) O2 c) CO2 d) H2O

a) N2

Which one of the following is considered to be a molecular compound? a) PCl3 b) NaBr c) Al2O3 d) Mg3P2

a) PCl3

Which country has the highest per capita emission of carbon dioxide? a) US b) Germany c) Canada d) Saudi Arabia

a) US

Increasing wavelength of light goes in this order. a) UV > visible > infrared b) Visible > infrared > UV c) infrared > visible > UV d) UV > infrared > visible

a) UV > visible > infrared

Which region of the UV spectrum is absorbed least by the atmosphere? a) UV-A b) UV-B c) UV-C d) they are all absorbed approx equally

a) UV-A

Which compounds are used in mineral-based sunscreens? a) ZnO and TiO2 b) ZnO and CdS c) TiO2 and SiO2 d) CdS and SiO2

a) ZnO and TiO2

Ozone in our atmosphere is important because it... a) absorbs some UV radiation b) helps trees grow c) reacts with excess CO2 d) reflects IR radiation

a) absorbs some UV radiation

Free radicals are... a) highly reactive chemical species b) species with unpaired electrons c) species such as H+ ad +OH d) all of these correctly describe free radicals

a) all of these are correct

P2O5 is the chemical formula for... 1) pentoxygen diphosphide 2) diphosphorus pentoxide 3) dioxygen pentaphosphide 4) monophosphorus pentoxide

2) diphosphorus pentoxide

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? a) by measuring the CO2 concentration in trapped air bubbles in the ice layers b) by measuring the 18O/16O ratio in the CO2 molecules c) By extrapolating the CO2 level from the temperature of the ice d) By extrapolating the CO2 level from the average global temperature

a) by measuring the CO2 concentration in trapped air bubbles in the ice layers

Currently, the primary source of sulfur dioxide emissions into the atmosphere is... a) coal burning power plants b) diesel trucks c) plastic manufacturing d) gasoline-powered lawnmowers

a) coal burning power plants

A substance that can be broken down into two or more simpler substances by chemical methods is called a(n)... a) compound b) mixture c) element d) isotope

a) compound

Oxidation and reduction of atoms involve a change in the number of ______ in the atoms. a) electrons b) protons c) neutrons d) nuclei

a) electrons

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. a) i and ii only b) i and iii only c) ii and iv only d) iii and iv only

a) i and ii only

Predict the shape of nitrous oxide, N2O. a) linear b) bent c) trigonal pyramidal d) trigonal planar

a) linear

The most numerous of the elements are... a) metals b) nonmetals c) metalloids d) noble gases

a) metals

In reference to waves, frequency is the... a) number of waves passing a fixed point in one second b) height of the wave c) distance between successive peaks in a wave d) distance between a peak in a wave to the next trough

a) number of waves passing a fixed point in one second

The Industrial Revolution is a key point in the Earth's atmospheric history because... a) prior to that time large deposits of petroleum and coal were not being used as energy sources b) the first atmospheric studies were conducted at that time c) spectrometers that could measure molecular response to infrared radiation were developed at that time. d) the first aircraft that could be used to collect atmospheric samples were developed at that time.

a) prior to that time large deposits of petroleum and coal were not being used as energy sources

Which air pollutant is the second-leading cause of lung cancer worldwide, behind tobacco smoke? a) Radon b) Ozone c) Carbon Monoxide d) Nitrogen oxides

a) radon

Which one of these materials is most likely to conduct heat? a) titanium rod b) sample of chlorine gas c) silicon water d) chunk of phosphorus

a) titanium rod

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? a) water vapor b) carbon dioxide c) nitrogen d) argon

a) water vapor

Choose the proper coefficients for each substance to balance this equation. ___ C2H4(g) + ___ O2(g) → ___ CO2(g) + ___ H2O(g) a) 1,1,2,2 b) 1,3,2,2 c) 2,3,4,2 d) 2,2,4,2

b) 1,3,2,2

What is the chemical formula for carbon disulfide? a) CH4 b) CS2 c) C2H6 d) H2SO4

b) CS2

The most abundant greenhouse gas in Earth's atmosphere is... a) CO2 b) H2O vapor c) N2 d) CH4

b) H2O vapor

The chemical formula for nitrogen monoxide is... a) N2o b) NO c) NO2 d) N2O3

b) NO

Arrange these types of radiation in order of increasing energy per photon: gamma rays, infrared radiation, radio waves, visible light, UV (ultra violet). a) Radio waves < visible light < UV < infrared radiation < gamma rays b) Radio waves < infrared radiation < visible light < UV < gamma rays c) Infrared radiation < radio waves < visible light < UV < gamma rays d) Gamma rays < infrared radiation < UV < radio waves < visible light

b) Radio waves < infrared radiation < visible light < UV < gamma rays

What contributes to the ozone hole? a) automobile exhaust b) Chlorofluorocarbons (CFCs) c) loss of northern forests d) all of these choices are correct

b) b) Chlorofluorocarbons (CFCs)

Which pollutant are you more likely to encounter in dangerous concentrations indoors rather than outdoors? a) nitrogen dioxide b) carbon monoxide c) ozone d) sulfur dioxide

b) carbon monoxide

What is the greatest source of indoor air pollution in developing countries? a) unvented space heaters b) cookstoves c) automobiles d) paint

b) cookstoves

Which type of material is defined as having a well-ordered atomic structure? a) amorphous b) crystalline c) transparent d) opaque

b) crystalline

Identify the single most effective strategy to reduce carbon dioxide emissions. a) use methane rather than gas for fuels in cars and trucks b) develop alternate energy sources that do not rely on fossil fuels c) use wood as home heating fuel d) convert all vehicles to diesel fuel

b) develop alternate energy sources that do not rely on fossil fuels

On a Periodic Table, the columns of elements with similar properties are... a) periods b) groups c) rows d) metals

b) groups

Chlorofluorocarbons rise to the stratosphere and... a) react directly with stratospheric ozone to destroy it b) interact with UV energy to produce free radicals that destroy ozone c) interact with UV energy to produce free radicals that react with oxygen to create ozone d) react with free radicals to remove carbon dioxide

b) interact with UV energy to produce free radicals that destroy ozone

Based on its name, which carbon compound contains the fewest carbon atoms? a) ethanol b) methane c) chlorobutane d) propyl alcohol

b) methane

Ozone is a secondary pollutant. A secondary pollutant is... a) not as hazardous as a primary pollutant b) not produced directly but as the product of the interaction of two or more pollutants c) one that is naturally present in our atmosphere d) one that is less hazardous than a primary pollutant

b) not produced directly but as the product of the interaction of two or more pollutants

The atomic number is the... a) same as the mass number of an atom b) number of protons in a nucleus c) number of protons and neutrons in a nucleus d) number of neutrons in a nucleus

b) number of protons in a nucleus

When only one pair of shared electrons is involved in a covalent bond, the linkage is called a bond. a) triple b) single c) double d) resonant

b) single

How do mineral nanoparticles in sunscreens protect from UV radiation? a) the particles scatter incoming UV light b) the particles absorb incoming UV light c) the particles dissolve with incoming UV light d) none are correct

b) the particles absorb incoming UV light

Determine the shape or geometry of PH3. (Hint: Use the Periodic Table to arrive at the electron configuration for phosphorous.) a) tetrahedral b) trigonal pyramidal c) bent d) trigonal planar

b) trigonal pyramidal

DNA, the genetic material of living organisms, is damaged by light in the... a) visible region of the spectrum b) ultraviolet region, especially below a wavelength of 320 nm c) ultraviolet region, especially above a wavelength of 340 nm d) infrared region of the spectrum

b) ultraviolet region, especially below a wavelength of 320 nm

This is the Lewis structure for acetic acid. The bond angles are not drawn to scale. *insert image here* Based on the electronic configuration shown in the Lewis structure, predict the O-- C--O bond angle, in degrees. a) 90 b) 109.5 c) 120 d) 180

c) 120

Which is the correct balanced equation for the complete combustion of ethane in excess oxygen? a) CH4+2O2 --> CO2+2H2O b) 2CH4+3O2 --> 2CO+4H2O c) 2C2H6+7O2-->4CO2+ 6H2O d) 2C2H6+5O2-->4CO+ 6H2O

c) 2C2H6+7O2-->4CO2+ 6H2O

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? a) CO2 molecules are highly symmetrical b) CO2 has low molar mass c) CO2 exists in relatively high concentrations d) CO2 is formed in the combustion of fossil fuels

c) CO2 exists in relatively high concentrations

Which one of the following compounds is considered to be an ionic compound? a) NO b) CCl4 c) LiF d) Pl3

c) LiF

Which substance is an element? a) NO2 b) NaCl c) N2 d) CH4

c) N2

Which two gases make up more than 95 percent of an inhaled breath? a) NO2 and N2 b) CO2 and O2 c) O2 and N2 d) N2 and Ar

c) O2 and N2

Which of the following is most biologically damaging type of radiation? a) UV-A b) UV-B c) UV-C d) infrared

c) UV-C

Which statement is correct? a) UV-A is the most energetic of the three forms of UV light b) UV-B is the most energetic of the three forms of UV light c) UV-C is the most energetic of the three forms of UV light d) UV-A, UV-B, UV-C are equally energetic

c) UV-C is the most energetic of the three forms of UV light

Which is not a pure substance? a) helium b) copper wire c) air d) sucrose

c) air

The greenhouse effect refers to the process by which... a) atmospheric oxygen and nitrogen absorb heat radiated by Earth b) atmospheric nitrogen absorbs UV radiation radiated by Earth c) atmospheric gases trap and return infrared radiation radiate by Earth d) greenhouse gases absorb UV radiation from the Sun, warming the molecules

c) atmospheric gases trap and return infrared radiation radiate by Earth

The two chemical bonds and geometry of water are best represented by... a) unequally linear b) equally linear c) bent d) unequally bent

c) bent

Light behaves like... a) a particle b) a wave c) both a particle and a wave d) neither a particle nor a wave

c) both a particle and a wave

Which explanation accounts for the fact that, on average, cloudy nights are warmer than clear nights? a) clouds reflect light incoming from the moon b) H2O does not absorb infrared energy c) clouds are composed of water vapor and H2O is a strong greenhouse gas d) clouds have a high concentration of carbon dioxide from fossil fuel combustion

c) clouds are composed of water vapor and H2O is a strong greenhouse gas

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... a) cradle-to-grave b) reusability c) cradle-to-cradle d) cost-benefit analysis

c) cradle-to-cradle

Wavelength is the... a) number of waves passing a fixed point in one second b) height of the wave c) distances between successive peaks in a wave d) distance between a peak of one wave and the next trough

c) distances between successive peaks in a wave

The "ozone" layer is found... a) only around the equator b) in the troposphere c) in the stratosphere d) in the mesosphere

c) in the stratosphere

What diagram(s) best represent(s) only molecules?

I (image that looks like 2 fidget spinners) and II (2 diatomic ions)

Which square(s) contain(s) only one or more compounds?

I only (like a pyramid with black dot in the middle and 2 white dots connected to the black one)

Which square(s) contain(s) only an element? *there are 4 images*

II only (all white)

Which squares contain mixtures? *there are 4 images*

III and IV only III has 3 black dots and 2 white dots that are stuck together IV has 4 dots stuck together

Land use changes have a big impact on global warming because of their effect on albedo. Albedo... a) is the primary wave number at which a greenhouse gas absorbs infrared radiation. b) describes the effectiveness of a molecule as a greenhouse gas. c) is the ratio of electromagnetic radiation reflected by a surface to the amount of radiation hitting that surface. d) describes the tendency of an atmospheric molecule to react with other atmospheric molecules, reducing their global atmospheric lifetimes.

c) is the ratio of electromagnetic radiation reflected by a surface to the amount of radiation hitting that surface.

A(n) _______ is a fixed number of atoms held together by chemical bonds in a certain spatial arrangement. a) element b) ion c) molecute d) mixture

c) molecule

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? a) the thickness b) the carbon dioxide concentration c) the 1H/2H ratio d) the temperature

c) the 1H/2H ratio

What distinguishes the atoms of one element from another? a) the number of neutrons b) the number of protons plus neutrons c) the number of protons d) the number of neutrons plus electrons

c) the number of protons

When assessing the risk of an air pollutant, which does not play a role in considering someone's exposure to the pollutant? a) a person's lung capacity b) a person's breathing rate c) the toxicity of the pollutant d) the concentration in air of the pollutant

c) the toxicity of the pollutant

Why are HFCs inappropriate for long-term replacement of CFCs? a) they are flammable b) they are very toxic c) they absorb infrared radiation d) they are an appropriate replacement

c) they absorb infrared radiation

In the periodic table, which elements typically have similar properties? a) those in the same rows b)those related diagonally c) those in the same columns d) those on opposite sides

c) those in the same columns

Which of the following would be described as "fine particles?" a) SOx b) NOx c) O3 d) 2.5 µm diameter soot

d) 2.5 µm diameter soot

Which component of the air makes up approximately 100 times more of an exhaled breath then of an inhaled breath? a) Ar b) O2 c) O3 d) CO2

d) CO2

How many protons, neutrons, and elections are there in a neutral atom of 19/9 F? a) A b) B c) C d) D

d) D (9 p, 10 n, 9 e)

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? a) excess precipitation could cause flooding b) the cold air increases the chance for snowstorms c) heatwaves can occur d) air pollution concentrates in the inversion layer

d) air pollution concentrates in the inversion layer

Which chemical components are given off in car exhaust? a) CO2 b) H2o c)NOx d) all of these are correct

d) all of these are correct

Decreased stratospheric ozone concentrations may lead to... a) increased incidences of melanomas b) harm to young marine life c) an increased occurrence of cataracts d) all of these choices are correct

d) all of these choices are correct

In their fifth and most recent report published in 2014, the vast majority of scientists agreed on several key points. Which of the following is NOT one of those points? a) If the rate of greenhouse gas emissions is not curtailed, our water resources, food supply, and even our health will suffer b) Human activities (primarily the combustion of fossil fuels and deforestation) are responsible for much of the recent warming c) The earth is getting warmer d) All of these choices are correct

d) all of these choices are correct

Which is correct? a) ozone forms by combining an oxygen atom with an oxygen molecule b) there is dynamic steady state of ozone in the stratosphere c) UV radiation will dissociate ozone into an oxygen atom and an oxygen molecule d) all of these are correct

d) all of these choices are correct

Which of the following are ways that aerosols may affect climate? a) scattering incoming radiation b) nucleation of clouds c) absorbing incoming radiation d) all of these choices are correct

d) all of these choices are correct

The structure of ozone most closely resembles a... a) linear molecule with different lengths of chemical bonds b) linear molecule with the same length of chemical bonds c) bent molecule with different lengths of chemical bonds d) bent molecule with the same length of chemical bonds

d) bent molecule with the same length of chemical bonds

What term is defined as the flow of electrons from one location to another? a) resistance b) transparency c) density d) electricity

d) electricity

Which process plays the most important role in the greenhouse effect? a) energy from the sun is reflected back into the atmosphere b) energy from the sun is absorbed by the earth c) energy from the sun is absorbed by the atmosphere d) energy is radiated by the earth is absorbed by the atmosphere

d) energy is radiated by the earth is absorbed by the atmosphere

What are the three pillars of sustainability? a) reduce, reuse, recycle b) equitability, justice, quality of life c) diversity, efficiency, toxicity d) environmental, social, economic

d) environmental, social, economic

In order to make useful predictions, which factors must be accounted for by climatic models? i. Aerosol Emissions ii. Land Use iii. Solar Irradiance a) ii only b) ii and iii only c) i and iii only d) i, ii and iii only

d) i, ii 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 a) iv only b) ii and iii only c) iii and iv only d) i, ii, iii, iv

d) i, ii, iii, iv

Identify possible consequences of global warming. i. A rise in sea level ii. An increase in average relative humidity iii. An increase in forest growth in the Northern Hemisphere iv. A weakening of ocean currents a) i and iii only b) i and iv only c) i, ii and iv only d) i, ii, iii, iv only

d) i, ii, iii, iv only

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 a) i only b) i and ii only c) ii only d) i, iii, and iv only

d) i, iii, and iv only

What is the effect of the absorption of infrared energy on matter? a) it excites bonding electrons b) it increases molecular rotation c) it breaks chemical bonds d) it increases the vibration of chemical bonds

d) it increases the vibration of chemical bonds

Carbon cycle refers to the... a) mechanism by which carbon dioxide causes global warming b) frequency of light energy that affects the rotational energy of carbon dioxide c) oxidation of glucose to form carbon dioxide and water d) movement of carbon through living organizations, the atmosphere, the sea and the Earth

d) movement of carbon through living organizations, the atmosphere, the sea and the Earth

The nucleus of an atom contains... a) electrons and protons only b) protons only c) electrons, protons, and neutrons d) protons and neutrons only

d) protons and neutrons only

What is not a mixture? a) a jar filled with rocks and sand b) sea water c) a glass of kool-aid d) sodium chloride

d) sodium chloride

Green chemistry is... a) the study of how to improve the production of oxygen via photosynthesis b) any chemistry having an agricultural base c) the cause of the higher temperatures and humidity typically found in greenhouses d) the design of products and processes that reduce hazardous substances

d) the design of products and processes that reduce hazardous substances

In metropolitan areas, the concentration of ozone in the atmosphere drops at night. Why? a) wind blows away the ozone at night b) energy usage goes down at night c) there are less cars on the road at night d) the formation of ozone requires sunlight

d) the formation of ozone requires sunlight

What two factors are considered when determining the risk assessment for air pollutants? a) exposure and ppm b) percentage and ppm c) toxicity and percentage d) toxicity and exposure

d) toxicity and exposure

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.") a) 7 b) 9 c) 11 d) 13 e) 15

e) 15

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? a) Cutting energy usage in the world's buildings by 20-25 percent below business-as-usual b) Having all cars get 60 mpg instead of 30 mpg c) Replacing 700 large coal-burning power plants with nuclear, wind, or solar power d) capturing and sequestering carbon dioxide at 800 coal-burning power plants e) none of these choices would provide the needed 9 billion tons

e) none of these choices would provide the needed 9 billion tons

Which is the correct Lewis structure? there are 4 images

the correct one has H then one bond then Cl with three lone pairs

Which shows the balanced equation for the reaction of nitrogen ( ), as it is normally found in our atmosphere, with oxygen ( ), as it is normally found in our atmosphere, to form nitrogen dioxide? there are 4 images

the image with 2 black dots + 2 white dots + 2 white dots --> nitrogen dioxide

Which one is the lewis structure for ozone? there are 4 images

n/a