Chemistry in Context overview all
the more toxic the pollutant, the lower the concentration level must be set
How does concentration in air affect exposure?
Indoor air has less ozone, sulfur dioxide, and nitrogen oxide because they're reactive pollutants, but has more carbon monoxide
How does indoor air differ from outdoor air?
higher concentrations of a pollutant can be tolerated only briefly. A pollutant may have several standards, each for a different length of time
How does length of time affect exposure?
It forms both naturally and as a result of human activities
How does ozone form?
Because sunlight is involved in ozone formation, the concentration of ground-level ozone varies with weather, season, and latitude.
How does ozone formation vary? Why?
If air quality is poor, reducing activity (which increases breathing rate) reduces exposure
How does rate of breathing affect exposure?
It contains chemical compounds that absorb UV-B radiationa nd UV-A radiation
How does sunscreen work?
the reactive hydroxyl radical (-OH), present in tiny amounts of air, combines with VOCs to form reactive molecule A, which combines with O2 to make A', and A' + NO -> A'' + NO2
How does the conversion of NO to NO2 connect to the breakdown of VOCs in the air?
It travels in specific circular orbits, and is stable only in these orbits and not in between.
How does the electron travel around the nucleus, according to Niels Bohr?
It lists them in order of increasing atomic number
How does the periodic table list elements?
It's gotten better
How has air quality changed over time?
Stratospheric concentration of ozone-depleting gases continued to rise steadily through 1990s, despite restrictions of Montreal Protocol
How has stopping the production of CFCs affected the stratospheric concentration of chlorine?
breathing and the burning of fuels
How is CO2 made?
In the stratosphere, it combines with O atoms to make •NO, nitrogen oxide
How is N2O implicated in ozone destruction?
N2 + O2, or on sunny days, some of the NO2 converts back into NO.
How is NO created? 2 ways.
2NO + O2 2NO2
How is NO2 NOT created?
NO + O3 NO2 + O2
How is NO2 created?
mass number
How is an isotope identified?
in relative units using a log scale
How is biological sensitivity expressed?
It undergoes a similar reaction to CFCs by acting as a catalyst in a cycle, but it is even MORE effective at destroying O3
How is bromine implicated in ozone destruction?
it is produced in the atmosphere from nitrogen monoxide, emitted both from the hot engines of vehicles and fires of coal-fired power plants
How is nitrogen dioxide produced?
produced directly in one step (e.g., CO and NO).
How is ozone created?
Radon is generated in the decay series of uranium
How is radon generated?
Like all noble gases, radon is colorless, odorless, tasteless, and chemically unreactive. But unlike the others, it is radioactive
How is radon similar to the other noble gases? How is it different?
Decreased stratospheric ozone over OSuth Pole leads to increased UV-B levels reaching Earth, and increased cancer rate in Southern Hemisphere countries
How is the ozone hole an example of the tragedy of the commons?
120 years
How long does it take a CCl2F2 molecule to decompose?
2 × 1017 CO molecules
How many CO molecules are in a single 500mL breath?
11 grams
How many grams of carbon are in a mole of gas?
2 × 1022 molecules and atoms
How many molecules and atoms are in an average breath of 500 mL?
in parts per billion
How should concentrations of sulfur dioxide and nitrogen dioxide be reported?
nitrous oxide, a naturally occurring compound of nitrogen that is produced in the soil and oceans by microorganisms and gradually drifts up into the stratosphere
N2O
one-billionth of a meter
Nanometer
•NO
Nitrogen monoxide
electrons in many molecules are arranged so that every atom (except hydrogen) shares in eight electrons
Octet rule
compound that always contains carbon, almost always contains hydrogen, and may contain elements such as oxygen and nitrogen
Organic compound
the angle of the earth with respect to the Sun and the distance between the sun and the earth
Ozone production increases with the intensity of the radiation striking the atmosphere, which in turn depends primarily on what?
ozone production increases with the intensity of the radiation striking the stratosphere, which in turn depends primarily on the angle of the Earth with respect to the Sun and the distance between the Sun and the Earth
Ozone production increases with what?
...
Plot the relative intensity of solar radiation as a function of wavelength.
principle that stresses the wisdom of acting, even in the absence of complete scientific data, before the adverse effects on human health or the environment become significant or irrevocable
Precautionary principple
pollutant produced directly in one step (e.g., CO and NO).
Primary pollutant
an energy distribution that is not continuous, but rather consists of many individual steps
Quantized
the entire collection of different wavelengths, each with its own energy
Radiant energy
Lewis structures that represent hypothetical extremes of electron arrangements in a molecule
Resonance forms
the process of organizing and evaluating scientific data to make informed predictions about risks to human health.
Risk assessment
a pollutant produced from chemical reactions involving one or more other pollutants (e.g., ozone)
Secondary pollutant
a digit that is included (or excluded) to correctly represent the accuracy with which an experimental quantity is known.
Significant figure
a representation of how the atoms in a molecule are connected. It is a Lewis structure from which the nonbonding electrons have been removed.
Structural formula
sulfuric acid
Sulfur dioxide produces what when it dissolves in water droplets?
lower, greater, ozone
The ____ the intensity of radiation of UV, the _____ amount of ____ in the air column
covalent bond
The two electrons shared in a molecule constitute what?
radioactive form of hydrogen that has two neutrons in its nucleus
Tritium
carbon-containing compounds that pass easily into the vapor phase
Volatile organic compound
substance that readily passes into the vapor phase; that is, it evaporates easily
Volatile substance
distance between successive peaks
Wavelength
1) number of molecules in reactants may differ from those in products, 2) physical states of reactants may differ from those in products
What 2 things may change in chemical equations?
1) identity of atoms in reactions = identity of atoms in products, 2) number of atoms of each element in reactants = number of atoms of each element in products, 3) mass of all reactants = mass of all products
What 3 things are always conserved in chemical equations?
Joining two ClO radicals to form ClOOCl
What accounts for 75-80% of stratospheric ozone depletion?
sulfuric acid
What acid is made from coal burning?
if the humidity is high enough, fine ash helps condense water vapor into an aerosol of tiny water droplets
What aids in the formation of aerosols?
From June to September, winds that circulate around the South Pole form a vortex that prevents warmer air from entering the region. As a result, temperature may drop as low as -90C.
What allows polar stratospheric clouds form?
Blended to make R-410A, a refrigerant and replacement for HCFC-22
What are C2HF5 and CH2F2 good for?
The prefixes di- and tri- specify the number of chlorine and fluorine atoms that substitute for hydrogen atoms of methane
What are chlorofluorocarbons' relationship to methane?
tobacco smoke, carbon monoxide, nitrogen oxide, VOCs
What are common indoor pollutants?
hydrochlorofluorocarbons
What are compounds of hydrogen, chlorine, fluorine, and carbon, used as a substitute for CFCs called?
hydrofluorocarbons (HFCs)
What are compounds of hydrogen, fluorine, and carbons, replacements for HCFCs called?
hydrogen, deuterium, and tritium
What are examples of isotopes?
silicon and germanium
What are examples of metalloids?
fire suppressants, especially in cases where hose or sprinkler system would be inappropriate
What are halons used for?
inert, nontoxic compounds that contain chlorine or fluorine (or both), as well as bromine
What are halons?
compounds of hydrogen, fluorine, and carbons, replacements for HCFCs
What are hydrofluorocarbons?
isotopes
What are hydrogen, deuterium, and tritium examples of?
NOx
What are nitrogen monoxide and nitrogen dioxide collectively known as?
Both waves and particles
What are photons?
thin clouds composed of tiny ice crystals formed from small amount of water vapor present in the atmosphere
What are polar stratospheric clouds?
1) In constant motion, 2) actually spaced quite far apart
What are some interesting qualities about atoms and molecules? 3 examples.
Chemical formula, Lewis structure, structural formula
What are the 3 different ways of demonstrating molecular structures?
1) Each chemical element has a unique set of chemical properties that distinguish it from every other element, 2) Elements with similar chemical properties are collected within the same group on the periodic table, 3) Each element is composed of a single type of atom. The chemical behavior of an element derives from the properties of the atoms
What are the 3 key principles about chemical elements?
resonance structures
What are the alternate forms of ozone called?
They are nontoxic, odorless, colorless, and don't burn
What are the benefits of CFCs?
Green, Yellow, Orange, Red, Purple, Maroon
What are the color ranges of the Air Quality Index?
1) Extreme cold, 2) Circular wind pattern, 3) Enough time for ice crystals to form and provide surface for reactions, 4) Darkness followed by rapidly increasing levels of sunlight
What are the four conditions for the creation of the ozone hole?
Carbon monoxide, nitrogen dioxide, ozone, particulate matter
What are the four outdoor pollutants?
0-50, 51-100, 101-150, 151-200, 201-300, 301-500
What are the numerical ranges of the Air Quality Index?
vertically electric, horizontally magnetic
What are the planes of an electromagnetic wave?
toxicity and exposure
What are the risks presented by an air pollutant a function of?
automobile exhaust, charcoal grills, propane camping stoves
What are the sources of carbon monoxide?
They don't contain chlorine atoms, nontoxic and nonflammable, and their hydrogen atoms facilitate decomposition in the lower atmosphere so they don't have long atmospheric lifetimes
What are the three benefits to HFCs?
concentration, length of time, breathing rate
What are the three components of exposure?
UV-A, UV-B, and UV-C
What are the three different types of UV radiation?
Observable (chemical phenomena), symbolic (PV=nRT), and explanatory (molecules and atoms)
What are the three levels of representation of chemistry?
1) Name each element in the chemical formula, modifying the name of the second element to end in -ide. 2) Use prefixes to indicate the number of atoms in the chemical formula. 3) Omit the prefix mono if there is only one atom for the first element in the chemical formula
What are the three rules for systematic names?
Carbon monoxide, photochemical smog, and sulfur dioxide
What are the three types of air pollution?
metals, nonmetals, and metalloids
What are the three types of elements in the periodic table?
Radon (Rn) and volatile organic compounds
What are the two indoor pollutants?
CCl3F and CCl2F2
What are the two most common types of CFCs?
CH2F2 (HFC-32) and C2HF5 (HFC-125)
What are the two new refrigerants?
quantum theory and wave model
What are the two theories for how to explain radiation?
systematic and common
What are the two types of names for substances?
as both a wave and as a particle
What are the two ways in which light can be described?
polar stratospheric clouds
What are thin clouds composed of tiny ice crystals formed from small amount of water vapor present in the atmosphere called?
coalescents, antifreeze, solvents (thinners)
What are three VOC additives in paint?
methane and octane
What are two examples of an organic compound?
Freon 11 (CCl3F) and Freon-12 (CCl2F2)
What are two examples of chlorofluorocarbons?
C2HF5 (HFC-125) and CH2F2 (HFC-32)
What are two examples of hydrofluorocarbons?
CHClF2 (HCFC-22) and C2H3Cl2F (HFCFC-141b)
What are two hydrochlorofluorocarbons?
chlorine and fluorine
What are two major elements in the halogen group?
motor vehicles and coal-fired plants that generate electricity
What are two major sources of air pollutants?
1) We like conveniences of modern life, 2) Some sources of air pollution are natural (lightning, volcanoes)
What are two reasons why no air pollution is unrealistic?
HCl (hydrogen chloride) and chlorine nitrate (ClONO2)
What are two stable compounds that chlorine and chlorine monoxide take in the stratosphere?
Chemical properties of an element and its locations in the periodic table
What arises from the arrangement of electrons within the atoms of the element? Two things.
carbon
What atom is black?
nitrogen
What atom is blue?
oxygen
What atom is red?
hydrogen
What atom is white?
sulfur
What atom is yellow?
UV rays of 220 nm or less
What breaks C-Cl bonds in CFCs?
Nothing, it's a natural process
What can be done about N2O creating •NO?
halogens
What chemical group are fluorine and chlorine part of?
HCl and ClONO2 into HOCl and Cl2
What chemical reactions take place on polar stratospheric clouds?
nitrogen dioxide
What compound has a characteristic brown color?
halons
What compound is used for fire suppressants?
chlorofluorocarbons
What compound is used for refrigerants?
Montreal Protocol
What convention had the goal of reducing CFC production to one-half of 1986 levels?
paints and varnishes
What creates VOCs inside?
cars
What creates VOCs?
forest fires in the summer, wood stoves in the winter, old diesel trucks, buses, tractors, construction sites, mining operations, unpaved roads, compound ammonia
What creates particulate matter?
atomic number (Z)
What defeines the identity of an atom?
Line spectrum
What demonstrtes only specific colors in a spectrum?
the shape of the energy distribution curve pictured in Figure 2.8could only be explained if the energy of the radiating body were the sum of many energy levels of minute but discrete size. In other words, the energy distribution is not really continuous, but consists of many individual steps. Such an energy distribution is called quantized.
What did Max Planck argue?
electron travels around nucleus in specific circular orbits, and electron is stable only in these orbits and not in between
What did Niels Bohr claim about electrons?
The energy of the electron orbits is quantized
What did Niels Bohr claim about the energy of electron orbits?
Proposed the first complete model for the structure of a hydrogen atom. Argued that electron travels around nucleus in specific circular orbits, and electron is stable only in these orbits and not in between. Energy of electron orbits quantized
What did Niels Bohr do?
Accelerated the timetable to completely ban production of CFCs
What did follow-up meetings after the Montreal Protocol do?
Bohr's theory
What did quantum mechanics replace?
Ozone hole in 1985
What did the British Antarctic Survey discover? When?
national air quality standards
What did the Clean Air Act establish?
It focused on preventing the formation of hazardous substances, stating that "pollution should be prevented or reduced at the source whenever feasible"
What did the Pollution Prevention Act do?
green chemistry
What did the Pollution Prevention Act provide the impetus for?
least reactive and most abundant
What differentiates O2 from the other types of elemental oxygen?
They participate in many reactions, including some that ultimately convert O3 to O2
What do H• and •OH radicals do in the stratosphere?
directly reveal the shape of a molecule
What do Lewis formulas NOT do?
platinum and rhodium
What do catalytic converters usually use as catalysts?
The greater effectiveness but lower concentration of bromine relative to chlorine in depleting stratospheric ozone
What do effective stratospheric chlorine values take into account?
arrangement of electrons within the atoms of the element
What do the chemical properties of an element and its locations on the periodic table arise from?
1) They make the formation of sulfur trioxide from sulfur dioxide and oxygen happen more quickly, 2) if the humidity is high enough, they help condense water vapor into an aerosol of tiny water droplets
What do the fine ash particles from burning coal end up doing? 2 things.
atoms and molecules
What do the symbols in a chemical equation represent?
It compares the time required to produce a sunburn on skin with and without sunscreen
What does SPF do?
sun protection factor
What does SPF stand for?
It pulls thymine together and creates a thymine dimer, leaving the DNA unable to replicate properly
What does UV radiation do to DNA?
The transformation of reactants into products
What does a chemical reaction involve?
The number of shells in an atom
What does a period reflect?
A sinusoidal variation of electric and magnetic fields in space
What does a single-frequency electromagnetic wave exhibit?
Electrons don't follow specific circular orbits, nor do they look like a solar system. The distribution of atoms is more a matter of probability and statistics
What does a typical atom look like?
always contains carbon, almost always contains hydrogen, and may contain elements such as oxygen and nitrogen
What does an organic compound contain?
conservation
What does any discussion of sustainability need to include?
it takes into account the relative natural abundance of isotopes, as well as their masses
What does each element's atomic mass on a periodic table take into account?
indicates air of hazardous quality, 301-500
What does maroon mean on the Air Quality Index? What number range maps to it?
characteristic brown color
What does nitrogen dioxide look like?
indicates air of unhealthy quality for certain groups, 101-150
What does orange mean on the Air Quality Index? What number range maps to it?
It has a sharp odor that impairs lung function and induces coughing, sneezing, and lung congestion
What does ozone do?
Ozone and nitrogen dioxide
What does photochemical smog create?
indicates air of very unhealthy quality, 201-300
What does purple mean on the Air Quality Index? What number range maps to it?
Radon causes lung cancer and is the second leading cause behind tobacco smoke
What does radon do to you?
indicates air of unhealthy quality, 151-200
What does red mean on the Air Quality Index? What number range maps to it?
the steady-state reaction of O3
What does the Chapman cycle explain?
0 to 500
What does the air quality index range from?
dominates both ozone production and seasons
What does the angle of the Earth with respect to the sun do?
because of the log scale, radiation at 280nm is 100,000 more damaging than radiation at 320nm
What does the biological sensitivity graph indicate about the difference between radiation at 280 nm and 320nm? Why?
Just a single proton in its nucleus
What does the hydrogen atom have in its nucleus?
group designation for given elements
What does the number of outer electrons correspond to?
the identity of the atom
What does the number of protons indicate?
Period or row
What does the number of shells in an atom correspond to in a periodic table?
Higher frequency carries higher energy, which means more electrons are displaced. Violet light, for instance, can displace electrons, but red light never will
What does the photoelectric effect argue?
Electrons do not have a precise location; electron position needs to be described in terms of probability. Electrons exist in orbitals with a specific energy and probability density in space.
What does the quantum mechanics model argue?
air currents and turbulent storms that turn and mix our air
What does the troposphere contain?
indicates air of moderate quality, 50-100
What does yellow mean on the Air Quality Index? What number range maps to it?
angle of Earth with respect to the sun
What dominates both ozone production and seasons?
Harm young marine life, suppresses plant growth, affect plankton growth and photosythensis (which has a huge ripple effect in food chain)
What effects does UV radiation have on non-humans?
Clean Air Act
What established national air quality standards?
double slit experiment
What experiment did Dr. Quantum do?
Chapman cycle
What explains the steady-sate reaction of O3 (formal term)?
alkali metals
What family is Group 1A?
alkaline earth metals
What family is Group 2A?
halogens
What family is Group 7A?
Not in the active form of Cl or ClO, but incorporated in stable compounds that do not destroy ozone
What form does chlorine in the stratosphere typically take?
carbon monoxide, ozone, sulfur dioxide, and nitrogen dioxide
What four gases contribute to air pollution at the surface of the earth?
octet rule
What generalization is useful for predicting Lewis structures and the formulas of compounds?
halogens
What group are fluorine and chlorine members of?
the average concentrations of stratospheric ozone began to decrease
What happened to the earth around 1980?
The water rippled out in waves, with the greatest intensity parallel to the slit. If the top of one wave meets the top of another wave, they cancel each other, and there appears an interference pattern on the wall. Places where the two tops meet have the highest intensity (the bright lines), and where they cancel are dark.
What happened when Dr. Quantum released a wave through one slit?
It began behaving like a particle instead of a wave
What happened when they tried to measure which slit electrons went through in Dr. Quantum's experiment?
From June to September, winds that circulate around the South Pole form a vortex that prevents warmer air from entering the region. As a result, temperature may drop as low as -90C. This allows polar stratospheric clouds to form
What happens during the Antarctic winter?
if the humidity is high enough, they help condense water vapor into an aerosol of tiny water droplets
What happens if fine ash particles are in the air when it's humid?
It can react with oxygen to form sulfur trioxide
What happens once sulfur dioxide is in the air?
The vast majority fall back to Earth's surface as rain or snow, but a few molecules go to the stratosphere, where H2O concentration is about 5ppm. At this altitude, photons of UV radiation trigger dissociation of water molecules into H• and •OH free radicals
What happens to H2O molecules that evaporate from oceans and lakes?
the energy provided by sunlight splits one of the bonds in the NO2 molecule into NO + O. The oxygen atoms produced then can react with oxygen molecules to produce ozone.
What happens to NO in the atmosphere?
On sunny days, some of the NO2 converts back into NO
What happens to NO2 on sunny days?
NO, rather than NO2, comes directly out of a tailpipe (or a smokestack). But over time and in the presence of VOCs and •OH, NO in the atmosphere is converted to NO2.
What happens to NO2?
UV-C is absorbed by O2, ozone layer absorbs most of UV-B, and most of UV-A reaches the Earth's surface
What happens to UV-A, B and C?
Absorbed into our blood via the lungs and reacts with the foods we eat to release energy to power the chemical processes within our bodies
What happens to oxygen when it goes through our lungs?
absorbed by O3 in the stratosphere
What happens to shorter wavelength solar radiation (<320nm)?
SO2 reacts with atmospheric oxygen to produce sulfur trioxide, one of the main causes of acid rain
What happens to sulfur dioxide after it's produced by a coal-burning power plant?
At this altitude, photons of UV radiation trigger dissociation of water molecules into H• and •OH free radicals
What happens to the few H2O molecules that go to the stratosphere?
steady state
What happens when a number of chemical reactions, typically competing reactions, balance each other?
Leaves as a particle, becomes a wave of potentials, goes through both slits, and interferes with itself to hit the wall like a particle
What happens when an electron is thrown through the two slits?
It dissolves in the moisture of your lungs to form sulfuric acid
What happens when sulfur dioxide enters your lungs?
Interferes with the ability of your hemoglobin to carry oxygen. You'll feel dizzy, nauseous, or stomach can hurt.
What happens when you inhale carbon monoxide?
U.S. Clean Air Act because it tries to limit the spread of hazardous substances or clean them up after the fact
What has been named as a "command and control law" or "end of the pipe solution"? Why?
reduced CO emissions and NO2 emissions
What has the requirement that all cars manufactured since the 70s have catalytic converters done?
chlorofluorocarbons
What human-made compound is thought to contribute to global warming?
ozone production increases with the intensity of the radiation striking the stratosphere, which in turn depends primarily on the angle of the Earth with respect to the Sun and the distance between the Sun and the Earth
What increases with the intensity of radiation striking the atmosphere?
A building that is air-tight with a limited intake of fresh air may have unhealthy levels of indoor air pollutants
What is "sick building syndrome"?
hydroxyl radical
What is -OH?
Avogadro's number is the number of particles found in one mole of a substance.
What is Avogadro's number?
the quantity of light absorbed by a substance dissolved in a nonabsorbing solvent is directly proportional to the concentration of the substance and the path length of the light through the solution
What is Beer-Lambert Law?
blowing agent to make foam insulation
What is C2H3Cl2F (HFCFC-141b) used for?
CCl3F
What is CFC-11?
CCl2F2
What is CFC-12?
Refrigerant, blowing agent for fast-food containers
What is CHClF2 (HCFC-22) used for?
Cl is both consumed and regenerated in the cycle, with no net change in concentration. Characteristic of a catalyst
What is Cl in the ozone depletion process outlined by Molina and Rowland?
C2H3Cl2F
What is HCFC-141b?
CHClF2
What is HCFC-22?
C2HF5
What is HFC-125?
CH2F2
What is HFC-32?
nitrogen monoxide and nitrogen dioxide
What is NOx?
resonance form
What is O3 an example of structurally?
steady state
What is O3's decomposition and formation an example of?
h
What is Planck's constant?
Measurement of how thick the ozone layer would be if it was at sea level
What is a Dobson unit?
chemical equation
What is a chemical reaction represented by?
Compound of hydrogen and carbon
What is a hydrocarbon composed of?
compounds of hydrogen, chlorine, fluorine, and carbon, used as a substitute for CFCs
What is a hydrochlorofluorocarbons?
Only demonstrates specific colors in a spectrum
What is a line spectrum?
1 x 10^-9 m
What is a nanometer equal to?
A row in the periodic table
What is a period?
electron shell
What is a region of space that can hold more than one electron?
period
What is a row in the periodic table called?
a region of space that can hold more than one electron
What is an electron shell?
ozone
What is an example of a secondary pollutant?
"dot" structure
What is another name for a Lewis structure?
Lewis structure
What is another name for a dot structure?
experiments in which damage to DNA is measured at various wavelengths
What is biological sensitivity to UV rays based on?
wave equation
What is c = called?
silent killer, as it has no color, taste, or smell
What is carbon monoxide's nickname? How did it get it?
They don't have chlorine
What is different about the new refrigerants?
a term reflecting both chlorine- and bromine-containing gases in the stratosphere
What is effective stratospheric chlorine?
the reactive hydroxyl radical (-OH), present in tiny amounts of air, combines with VOCs to form reactive molecule A, which combines with O2 to make A', and A' + NO -> A'' + NO2
What is hydroxyl radical?
only a proton
What is in the nucleus of the most common form of hydrogen?
photoelectric effect
What is it called when electrons are emitted from solids, liquids or gases when they absorb energy from light?
Wave and a particle
What is light's duality?
high temperature, such as a jet engine
What is needed N2+ O2 for to become NO?
ozone is much more chemically reactive
What is one difference between ozone and oxygen?
Many of the CFCs have very long atmospheric lifetimes
What is one reason for the slow rate of change in chlorine levels after the Montreal Protocol?
hydrochlorofluorocarbons
What is one substitute for CFCs?
Particulate matter comes in a range of sizes, but only the tiny particles (PM10 and PM2.5) are regulated as pollutants.
What is particulate matter?
Type of air pollution consisting of tiny particles of solid or liquid suspended in air, "aerosol"
What is particulate matter?
aerosol
What is smoke an example of?
the energy provided by sunlight splits one of the bonds in the NO2 molecule into NO + O. The oxygen atoms produced then can react with oxygen molecules to produce ozone.
What is sunlight's role in ozone formation?
nitrogen dioxide
What is the "brown haze"?
Two sets of data from Antarctic, one for O3 concentrationa nd the other for ClO-, plotted versus latitude at which samples were measured. As stratospheric O3 concentration decreases, chlorine's increases in a mirror image pattern
What is the "smoking gun"?
When graphed against one another, stratospheric chlorine levels and ozone levels are mirror images of each other
What is the "smoking gun"?
color-coded index scaled from 1-500, with value of 100 pegged to national standard for pollutant. Green or yellow (<100) indicates air of good or moderate quality. Orange indicates that the air has become unhealthy for some groups. red, purple, and maroon (>150) means the air is unhealthy for everyone to breathe
What is the Air Quality Index?
by the least accurate piece of data that goes into it
What is the accuracy of a calculation limited by?
CCl2F2 + UV photon (less than 220nm) CCIF2 + -Cl. Then 2Cl + 2O3 2ClO + 2O2. Then ClO + ClO ClOOCl. Then ClOOCl + UV photon ClOO + Cl. Then ClOO + UV photon Cl + O2.
What is the actual mechanism for CFC's depletion of ozone?
Reduces molecular stability and promotes destruction of compounds at low altitudes
What is the benefit introducing hydrogen atoms in place of a halogen atom problematic when coming up with a substitute for CFCs?
They decompose in the troposphere more readily than CFCs and hence do not accumulate to the same extent in the stratosphere
What is the benefit of HCFCs?
Chlorine radical
What is the catalyst in ozone depletion?
energy + 3O2 2O3
What is the chemical equation for creating ozone?
H2O +SO3 -> H2SO4
What is the chemical equation for sulfuric acid?
78% nitrogen, 21% oxygen, 1% other gases, percent meaning parts per hundred
What is the composition of dry air by volume?
it makes them highly reactive
What is the consequence of free radical's unpaired electrons?
air pollutants can accumulate there
What is the danger of an inversion layer?
80km
What is the diameter of the mesosphere?
50km
What is the diameter of the stratosphere?
12km
What is the diameter of the troposphere?
a secondary pollutant is produced from chemical reactions involving one or more other pollutants (e.g., ozone). In contrast, primary pollutants are produced directly in one step (e.g., CO and NO).
What is the difference between a primary and secondary pollutant?
fluorine is highly reactive, but CFCs aren't
What is the difference between fluorine and chlorofluorocarbons?
Halogens are very reactive in their elemental state, whereas CFCs are very unreactive
What is the difference between halogens and CFCs?
Halons contain bromine
What is the difference between halons and CFCs?
Halons contain bromine
What is the difference between halons and halogens?
difference in mass because of different numbers of neutrons
What is the difference between isotopes? Why?
The distribution of atoms is more a matter of probability and statistics
What is the distribution of atoms like?
They still contain chlorine, so they still have adverse effects on the ozone layer and therefore can only be regarded as an interim solution
What is the downside of HCFCs?
A building that is air-tight with a limited intake of fresh air may have unhealthy levels of indoor air pollutants
What is the downside of energy-efficient buildings?
quantized
What is the energy of electron orbits like, according to Niels Bohr?
E = hc/ λ
What is the equation for energy?
E=h
What is the equation for energy?
ν = c/ λ
What is the equation for the relationship between frequency and wavelength (symbol)?
frequency = speed of light / wavelength
What is the equation for the relationship between frequency and wavelength, long form?
use less energy, create less waste, use fewer resources, and use renewable resoures
What is the goal of green chemistry?
a series of reactions involving water vapor and its breakdown products
What is the greatest natural cause of ozone destruction wherever it takes place across the globe?
It is the simplest hydrocarbon and the primary component of natural gas
What is the importance of methane?
O2
What is the least reactive type of elemental oxygen?
particulate matter
What is the least understood of the five air pollutants?
The need to find energy sources that are both clean and sustainable
What is the major challenge of the century?
A decrease in ozone and an increase in chlorine monoxide as the South Pole is approached
What is the major effect of the "smoking gun" graph?
O2
What is the most abundant form of elemental oxygen?
Melanoma
What is the most common form of cancer?
Melanoma
What is the most dangerous form of skin cancer?
Reactions with free radicals H• and •OH
What is the most efficient mechanism for destroying ozone at altitudes above 50km?
meth means 1 carbon atom, eth- means 2 carbon atoms, prop- is 3, but- is 4
What is the naming scheme for hydrocarbons?
2O3 3O2. Cl acts as a catalyst and isn't used up in the equation
What is the net equation of CFCs and ozone?
2O3 3O2
What is the net result of CFCs and ozone?
for predicting Lewis structures and the formulas of compounds
What is the octet rule useful for?
the most common form of hydrogen, which only has one proton in its nucleus
What is the one and only atom that doesn't also have a neutron?
The orbital for the one-electron H atoms is spherical...other atoms have electron orbitals with different shapes.
What is the orbital for the one-electron H atom like?
nitrogen and oxygen found in air, which chemically combine in the presence of something very hot, like automobile engine or forest fire
What is the origin of nitrogen monoxide (nitric oxide)?
Electrons are emitted from solids, liquids or gases when they absorb energy from light
What is the photoelectric effect?
methane
What is the primary component of natural gas?
They're greenhouse gases. They absorb infrared radiation like CO2, trap heat in atmosphere, and contribute to global warming. Aren't long-term solutions either
What is the problem with HFCs?
It only applies accurately to an H atom which has a single electron. If we add more, the theory breaks down.
What is the problem with Niels Bohr's theory?
Too many chlorine atoms increases toxicity
What is the problem with adding more chlorine atoms to a CFC substitute?
they are refrigerant gases and mixed with tons of other things, like aerosol spray cans
What is the purpose of chlorofluorocarbons?
Beer-Lambert Law
What is the quantity of light absorbed by a substance dissolved in a nonabsorbing solvent is directly proportional to the concentration of the substance and the path length of the light through the solution called?
below 2, above 11. The lower the number, the better
What is the range of UV index? What's worst? Least worst?
inversely proportional
What is the relationship between ?
Because atoms bonded together will share electrons, the resulting molecule will have lower energy than the sum of the atoms alone, and thus the molecule with its bonded atoms will be more stable than the separate atoms
What is the relationship between energy, atoms, and molecules?
a given percent decrease in stratrospheric ozone is expected to increase the biological damage done by UV radiation by twice that percentage
What is the relationship between stratospheric ozone and biological damage?
The magnetic field is perpendicular to the electric field
What is the relationship between the magnetic field and the electric field in a wave?
Its bonds are somewhere between the strength of a single and double bond
What is the result of ozone having resonance structures?
Bent at an angle of about 120 degrees
What is the shape of an ozone molecule?
When sunlight returns, the light splits HOCl and Cl2 to release chlorine atoms. Given the increase in Cl radicals, the hole starts to form
What is the significance of September in the Antarctic?
Chemical reactions that occur on the surface of these ice crystals convert molecules that don't deplete ozone, like ClONO2 and HCL, to the more reactive species that do, HOCL and Cl2
What is the significance of polar stratospheric clouds?
From June to September, winds that circulate around the South Pole form a vortex that prevents warmer air from entering the region. As a result, temperature may drop as low as -90C. This allows polar stratospheric clouds to form
What is the significance of wind in the Antarctic?
methane
What is the simplest hydrocarbon?
Destruction
What is the sink portion of the Chapman cycle?
Creation
What is the source portion of the Chapman cycle?
3.00 * 10^8 meters per second
What is the speed of light?
3.00 × 10^8 m•s−1
What is the speed of light?
-OH
What is the symbol for the hydroxyl radical?
c
What is the symbol for the speed of light?
effective stratospheric chlorine value
What is the term reflecting both chlorine- and bromine-containing gases in the stratosphere?
When exposed to water, they explode. The further you go down in the group, the more explosive the reaction
What is the trend among alkali metals?
particulate matter
What is the type of air pollution consisting of tiny particles of solid or liquid suspended in air, "aerosol," called?
infrared at 53%
What is the vast majority of the total energy emitted by the Sun radiated to the earth as? How much?
24.5L at 25C
What is the volume of 1 mole of gass?
.5 liters
What is the volume of a breath?
3.78L
What is the volume of a typical breath?
c =
What is the wave equation for EM waves?
1 a.m.u.
What is the weight of a neutron?
1 a.m.u.
What is the weight of a proton?
1/1800 a.m.u.
What is the weight of an electron?
...
What is the width of a human hair?
The further you go down the group, the denser the gases become
What is trend among noble gases?
Chapman cycle
What is triggered when an O2 molecule absorbs a photon of UV-C light, splitting into two O atoms. These in turn react with O2 to form O3?
They are the only halogens that are also gases
What is unique about fluorine and chlorine relative to other halogens?
U.S. Clean Air Act
What led to the establishment of air quality standards?
catalytic converter
What lowers NO2 emissions by catalyzing conversion back to N2 and O2?
The C-Cl and C-F bonds are so strong that the molecules are virtually indestructible
What makes CFCs indestructible?
jet engines. N2+ O2 -high temperature 2NO
What manmade thing creates NO? How, in a chemical formula way?
atomic number
What number CANNOT vary for an element?
mass number
What number can vary for an element?
carbon monoxide is odorless, but the other three have odors
What odors do carbon monoxide, ozone, sulfur dioxide, and nitrogen dioxide have?
tropics
What part of the world has highest radiation intensity during the equinox?
nontropical areas
What part of the world has the highest radiation intensity during the summer solstice?
38%
What percentage of the energy from the sun comes to us as visible light?
53%
What percentage of the total energy emitted by the sun is infrared?
particulate matter
What pollutant do forest fires create?
particulate matter
What pollutant do old diesel trucks create?
VOCs
What pollutant do paints and varnishes make?
particulate matter
What pollutant do wood stoves create?
particulate matter
What pollutant does compound ammonia create?
nitrogen dioxide
What pollutant has a brown haze?
carbon monoxide
What pollutant is most common indoors?
Nitrogen and ozone
What pollutants are measured in ppb?
their chemical inertness. The C-Cl and C-F bonds in the CFC molecules that they'e essentially
What property makes CFCs so harmful to the atmosphere?
Included a provision to hold future meetings to revise goals as new scientific knowledge evolved.
What provision did the Montreal Protocol include?
electron shell
What replaces the electron orbit?
bent
What shape is an O3 molecule?
Pollution Prevention Act
What significant piece of legislation followed the Clean Air Act?
They came out exactly in the same line
What sort of line did marbles make with only one slit in Dr. Quantum's experiment?
they came out in two identical lines parallel to the slits
What sort of lines did marbles make with two slits in Dr. Quantum's experiment?
sunlight
What splits NO2?
scientists replaced the concept of an electron orbit with an electron shell - this is a region of space that can hold more than one electron.
What theory replaced Niels Bohr's theory?
quantum mechanics
What theory was developed in the 1920s to explain properties of atoms?
1) identity of atoms in reactants = identity of atoms in products, 2) number of atoms in each element in reactants = number of atoms in each element in products, 3) mass of all reactants = mass of all products
What three things are always conserved in chemical reactions?
Flammability, toxicity, and extreme stability
What three undesirable values did chemists take into account when synthesizing substitutes for CFCs?
1) concentration in air, 2) length of time, 3) rate of breathing
What three ways can you assess exposure?
sulfur dioxide and nitrogen dioxide
What two compounds produce acid rain?
Sherwood Rowland and Mario Molina
What two people realized how ozone depletion was occurring?
1) They require the consumption of resources, and 2) the creation of waste
What two things do most human activities have in common?
Toxicity and exposure
What two things does risk from air pollution depend on?
Wave and a particle
What two things is light (NOT electromagnetic)?
number of molecules, physical states
What two things might change in a chemical reaction?
hydrogen (H•) and hydroxyl (•OH)
What two types of free radicals do H2O molecules turn into in the stratosphere? Why?
diatomic molecules
What type of molecules are halogens in their elemental state?
secondary pollutant
What type of pollutant is ozone?
electromagnetic
What type of wave is light?
CCl2F2 destroyed by UV to create CClF2 + Cl, then Cl + O3 ClO + O2, then ClO + O Cl- + O2
What was Rowland and Molina's original hypothesis for ozone depletion?
UV radiation makes chlorine atom break away from the CFC molecule. The chlorine atom reacts with ozone molecule to form chlorine monoxide and diatomic oxygen. When a free atom of oxygen reacts with chlorine monoxide molecule, diatomic oxygen is formed and chlorine atom is released to destroy more ozone
What was Sherwood Rowland and Mario Molina's original proposal for the reaction mechanism? Long form.
UV ray + CFC Cl, then Cl + O3 ClO + O2, then O + ClO O2 + Cl
What was Sherwood Rowland and Mario Molina's original proposal for the reaction mechanism? Short form.
CHClF2 (HCFC-22), with an ozone depleting potential about 5% that of CFC-12 and atmospheric lifetime of 20 years
What was once the most widely used HCFC? Why?
Vienna Convention on Protection of the Ozone Layer
What was the first ever convention on ozone depletion?
By 1998, reduce CFC production to one-half of 1986 levels
What was the goal of the Montreal Protocol?
Stop production of CFCs
What was the key initial strategy for reducing chlorine in the stratosphere?
It wasn't stringent enough, so subsequent meetings accelerated stoppage of CFCs and added other substances to the ban list
What was the problem with the Montreal Protocol?
visible region
What wavelength distribution has the greatest intensity from the sun?
photons of 320nm or less, whereas 242nm are needed for O2.
What wavelength is necessary to break the O-to-O bond in ozone? How does this compare to O2?
Refrigeration, foam cushions, propellants in aerosol spray, nontoxic solvents for oil and grease
What were CFCs used for?
Used as refrigerant molecules, propellant gases in aerosol cans, and making Styrofoam
What were chlorofluorocarbons used for?
They were used as fire suppressants
What were halons used for?
halons
What were used as fire suppressants?
CFCs
What were used as refrigerants?
Will eventually be phased out by 2030
What will happen to HCFCs, according to policy?
hydrofluorocarbons (HFCs)
What will replace HCFCs?
Pyrocool Fire-Extinguishing Foam
What will replace halons in fighting fires?
He got an interference pattern
When Dr. Quantum threw electrons at two slits, what happened?
long, sunny summer days, especially in urban areas
When are high levels of O3 most likely to occur?
a repeat in electronic arrangement
When chemical properties repeat themselves, this signals what?
black
When depicting atoms, what color is carbon?
white
When depicting atoms, what color is hydrogen?
blue
When depicting atoms, what color is nitrogen?
red
When depicting atoms, what color is oxygen?
yellow
When depicting atoms, what color is sulfur?
After December 31, 1995
When did countries agree to completely halt CFC production?
Series of meetings in the 2000s
When did countries agree to phase out other ozone-depleting chemicals?
In the late 1990s, then started decreasing
When did stratospheric chlorine levels peak?
1970s
When did sulfur dioxide peak?
1980s
When did the average concentrations of stratospheric ozone began to decrease?
When cooler air gets trapped beneath warmer air
When do air air inversions occur?
During spring at the South Pole, from September to November
When does a rapid ozone decline take place?
Particulate matter comes in a range of sizes, but only the tiny particles are regulated as pollutants
When is particulate matter a pollutant?
January
When is the Earth closest to the Sun?
July
When is the Earth farthest from the Sun?
The formation of ozone in the Chapman cycle is triggered when an O2 molecule absorbs a photon of UV-C light, splitting into two O atoms. These in turn react with O2 to form O3.
When is the formation of ozone in the Chapman cycle triggered?
summer solstice (June in northern hemisphere, December in southern) because the sun is never directly overheard
When is the maximum intensity of radiation for non-tropical areas? Why?
In early January, when the Earth is nearest Sun, compared with July, when the Earth is farthest away
When is there a slight (~7%) increase in solar power reaching earth? Why?
structural formula
When nonbinding electrons are removed from a Lewis structure, what do you have?
2070
When will the ozone hole be back to 1980 levels?
troposphere
Where are air currents and turbulent storms that turn and mix the air contained?
Electrons do not have a precise location; electron position needs to be described in terms of probability
Where are atoms' location in the quantum mechanics model?
They are primarily obtained from crude oil
Where are most of the hydrocarbons we use today obtained from?
emitted from substances
Where do indoor pollutants come from?
In cities ringed by mountains
Where do inversion layers (air inversions) occur?
Chemical reactions
Where do outdoor pollutants arise from?
from crude oil
Where do we get hydrocarbons?
Byproduct of coal combustion
Where does mercury come from?
originates from many sources, including truck and car engines, coal-burning power plants, fires, and blowing dust
Where does particulate matter come from?
Vehicle emissions and sunlight
Where does photochemical smog come from?
It occurs naturally in tiny amounts and usually is no problem. But it may reach hazardous levels in basements, mines, and caves
Where does radon form?
On average, the total O3 concentration is higher the closer one gets to either pole, with the exception of the seasonal ozone "hole" over the Antarctic.
Where does the total concentration of O3 get higher?
Most of it comes from nitrous oxide, N2O, which reacts with O atoms, but it also can come from jet engines
Where does •NO come from?
Antartica
Where is the "seasonal hole" of O3?
It occurs seasonally over the South Pole, with a minimum in late September/early October, the Antarctic spring
Where is the ozone hole? When does it occur?
Neils Bohr
Who argued that an electron travels around nucleus in specific circular orbits, and electron is stable only in these orbits and not in between?
Max Planck
Who argued that energy distribution is not really continuous, but consists of many individual steps?
Max Planck
Who argued that energy distribution is quantized?
Albert Einstein
Who argued that radiation should be viewed as constituted of photons?
Max Planck
Who argued that the shape of the energy distribution curve could only be explained if the energy of the radiating body were the sum of many energy levels of minute but discrete size?
Albert Einstein
Who came up with photons?
The presence of a dense nucleus in the center of the atom was demonstrated by scattering experiments performed by Rutherford and his students in 1909.
Who demonstrated the presence of a dense nucleus in the center of an atom?
Dupont in the 1930s
Who developed chlorofluorocarbons? When?
Dr. Quantum
Who did the double slit experiment?
Rowland, Molina, and Crutzen
Who discovered the major source of stratospheric ozone depletion?
British Antarctic Survey in 1985
Who first reported the "ozone hole"? When?
Neils Bohr
Who proposes the first completem odel for the structure of a hydrogen atom?
Niels Bohr
Who recognized that the H atom only has a single proton in its nucleus?
because of their unpaired electron
Why are free radicals highly reactive?
They have no mass
Why are photons not particles in the usual sense?
even this low concentration of CO contains a staggering number of carbon monoxide molecules. This seeming contradiction is a consequence of the minuscule mass of molecule
Why are the maximum concentrations of pollutants so tiny?
Equal volumes of gases contain equal numbers of molecules, provided gases are at the same temperature and pressure
Why can you represent the composition of air in terms of numbers of atoms and molecules present, as well as by volume?
Some VOCs are additives that evaporate as the paint dries, and also have antifreeze. allows the folks who live up north to store paint in their basements without worrying that it will be damaged by repeated freezing and thawing. Antifreeze also allows paint to be applied in colder weather and provides longer "open time," so that the paint does not dry out too quickly.
Why do VOCs exist in paints to begin with?
They are water-soluble and form far below highest levels of ozone concentration, so they are removed from the air when they wash out in the rain
Why do hydrogen chloride and chlorine nitrate not upset ozone balance?
On sunny days, some of the NO2 converts back into NO
Why do people refer to NOx, rather than to either NO or NO2?
Sunlight splits NO2 to release O atoms. These in turn react with O2 to form O3.
Why does ozone concentration drop off sharply at night?
Sunlight splits NO2 to release O atoms. These in turn react with O2 to form O3.
Why does ozone formation require sunlight?
Radon is generated in the decay series of uranium, another naturally occurring radioactive element. Because uranium occurs at a concentration of about 4 ppm in the rocks of our planet, radon is ubiquitous. Depending on how your apartment or dorm is constructed, the radon produced from uranium-containing rocks may find entry into the basement
Why does radon exist in caves and in basements?
sulfur trioxide dissolves readily in water droplets to produce sulfur acid
Why does sulfuric acid form?
Because sunlight is involved in ozone formation
Why does the concentration of ground-level ozone varies with weather, season, and latitude?
The air at the North Pole isn't nearly as cold and the air trapped over the Arctic generally begins to diffuse out of the region before the Sun gets bight enough to trigger as much ozone destruction
Why does the ozone hole not form in the Northern Hemisphere?
Because CFCs are nontoxic, nonflammable, cheap, and widely available, they revolutionized air conditioning, making it readily accessible for homes, office buildings, shops, schools, and automobiles. Beginning in the 1960s and 1970s, CFCs helped to spur the growth of cities in hot and humid parts of the world. In effect, a major demographic shift occurred because of CFC-based technology that transformed the economy and business potential of entire regions of the globe.
Why have CFCs been so important?
1) Improved engine design, 2) computerized sensors that better adjust fuel-oxygen mixture, 2) requirement that all cars manufactured since the 70s have catalytic converters
Why have CO emissions declined? 3 reasons.
Increased flammability, reduces total mass, and reduction of boiling point
Why is introducing hydrogen atoms in place of a halogen atom problematic when coming up with a substitute for CFCs?
allows the folks who live up north to store paint in their basements without worrying that it will be damaged by repeated freezing and thawing. Antifreeze also allows paint to be applied in colder weather and provides longer "open time," so that the paint does not dry out too quickly.
Why is there antifreeze (and therefore VOCs) in paints?
It replaced ammonia or sulfur dioxide, two toxic and corrosive refrigerant gases. In many respects, CCl2F2 was (and still is) an ideal substitute. It is nontoxic, odorless, colorless, and does not burn. It isn't toxic, either!
Why was the discovery of chlorofluorocarbons so great?
...
Write an equation for the reaction of sulfur dioxide into sulfur trioxide.
...
Write out the equation for methane combustion.
...
Write out the equation for octane combustion.
C4H10 + O2 CO2 + H2O
Write out the equation for the combustion of butane.
C2H5OH + O2 CO2 + H2O
Write out the equation for the combustion of ethanol.
C3H8 + O2 CO2 + H2O
Write out the equation for the combustion of propane.
Electromagnetic spectrum
a continuum of waves that ranges from short, high-energy X-rays and gamma rays to long, low-energy radio waves
Significant figure
a digit that is included (or excluded) to correctly represent the accuracy with which an experimental quantity is known.
Secondary pollutant
a pollutant produced from chemical reactions involving one or more other pollutants (e.g., ozone)
Structural formula
a representation of how the atoms in a molecule are connected. It is a Lewis structure from which the nonbonding electrons have been removed
when cooler air gets trapped beneath warmer air
air inversion
Ambient air
air surrounding us, usually meaning the outside air
Exposure
amount of substance encountered
Quantized
an energy distribution that is not continuous, but rather consists of many individual steps
thin veil between earth and outer space
atmosphere
designing chemical products and processes that reduce or eliminate the use or generation of hazardous substances
benign by design
Volatile organic compound
carbon-containing compounds that pass easily into the vapor phase
representation of a chemical reaction using chemical formulas
chemical equation
symbolic way to represent the elementary composition of a substance
chemical formula
Combustion
chemical process of burning; that is, the rapid combination of fuel with oxygen to release energy in the form of heat and light
Catalyst
chemical substance that participates in a chemical reaction and influences rate without itself undergoing permanent change
Coalescent
chemicals added to soften latex particles in paint so that these particles spread to form a continuous film of uniform thickness
Organic compound
compound that always contains carbon, almost always contains hydrogen, and may contain elements such as oxygen and nitrogen
Chlorofluorocarbons
compounds composed of the elements chlorine, fluorine, and carbon (but do not contain the element hydrogen)
Hydrocarbon
compounds made up only of elements hydrogen and carbon
Hydrochlorofluorocarbons
compounds of hydrogen, chlorine, fluorine, and carbon, used as a substitute for CFCs
Steady state
condition in which a dynamic system is in balance so that there is no net change in concentration of the major species involved
Nanotechnology
creation of materials at the atomic and molecular scale
Green chemistry
design of chemical products and processes to use less energy, produce fewer hazardous materials, and use less resources whenever possible. The desired outcome is to produce less waste, especially toxic waste, and to use fewer resources
Ozone layer
designated region in the stratosphere of maximum ozone concentration
Wavelength
distance between successive peaks
Octet rule
electrons in many molecules are arranged so that every atom (except hydrogen) shares in eight electrons
Metal
elements that are shiny and conduct electricity and heat well
Nonmetal
elements that do not conduct heat or electricity well and have no one characteristic appearance
Metalloids
elements that lie between metals and nonmetals on the periodic table and do not fall cleanly into either category
amount of substance encountered
exposure
tinier and more deadly particles of particulate matter, about PM2.5's size
fine particles
set of principles of guide all in the chemical community
green chemistry
Planck's constant
h
one of the reactive nonmetals in group 7A, such as fluorine, chlorine, bromine or iodine
halogen
Alkali metals
highly reactive metals with one outer electron
compounds made up only of elements hydrogen and carbon
hydrocarbons
Law of conservation and mass
in a chemical reaction, mass and matter are preserved. the mass of the reactants consumed equals the mass of the products formed
Photon
individual bundles of energy
Halon
inert, nontoxic compounds that contain chlorine or fluorine (or both, but no hydrogen). But in addition, they contain bromine
Toxicity
intrinsic health hazard of a substance
Aerosol
liquid and solid particles that remain suspended in air rather than settling out
Troposphere
lower region of the atmosphere in which we live that lies directly above the surface of the earth, accounting for the first six miles
millionth of a gram (mu g)
microgram
mu m, millionth of a meter. micron is another term for this unit
micrometer
another term for micrometer
micron
Microgram
millionth of a gram (mu g)
Diatomic molecule
molecule consisting of two atoms
Micrometer
mu m, millionth of a meter. micron is another term for this unit
Atomic number
number of protons in the nucleus of an atom
Frequency
number of waves passing a fixed point in 1 second
Noble gas
one of the inert elements in Group8A that undergoes few, if any, chemical reactions
Halogen
one of the reactive nonmetals in group 7A, such as fluorine, chlorine, bromine or iodine
Chemical symbol
one or two-letter abbreviations for the elements
Nanometer
one-billionth of a meter
Periodic table
orderly arrangement of all the elements based on similarities in their properties
complex mixture of tiny solid particles and microscopic liquid droplets
particulate matter
one part out of one billion, or 1000 times more concentrated than one part per million
parts per million
mixture
physical combination of two or more substances present in variable amounts
Precautionary principle
principle that stresses the wisdom of acting, even in the absence of complete scientific data, before the adverse effects on human health or the environment become significant or irrevocable
respiration
process by which the foods we eat are metabolized to produce carbon dioxide and water
Chemical reaction
process whereby substances described as reactants are transformed into different substances called products
Compound
pure substance made up of one or more different elements in a fixed, characteristic chemical combination
Alkaline metals
reactive metals with two outer electrons
Halogens
reactive nonmetals with 7 outer electrons
Chemical equation
representation of a chemical reaction using chemical formulas
Lewis structure
representation of an atom or molecule that shows its outer electrons
process by which the foods we eat are metabolized to produce carbon dioxide and water
respiration
the process of evaluating scientific data and making predictions in an organized manner about the probabilities of an outcome
risk assessment
Volatile substance
substance that readily passes into the vapor phase; that is, it evaporates easily
meeting the needs of the present without compromising the ability of future generations to meet their needs
sustainability
ν
symbol for frequency
c
symbol for speed of light
λ
symbol for wavelength
Chemical formula
symbolic way to represent the elementary composition of a substance
Scientific notation
system for writing numbers as product of a number and 10 raised to the appropriate power
Radiant energy
the entire collection of different wavelengths, each with its own energy
Chapman cycle
the first set of natural steady-state reactions proposed for stratospheric ozone
Risk assessment
the process of evaluating scientific data and making predictions in an organized manner about the probabilities of an outcome
Mass number
the sum of the number of protons and neutrons in the nucleus of an atom
Polar stratospheric clouds
thin clouds composed of tiny ice crystals formed from small amount of water vapor present in the atmosphere
intrinsic health hazard of a substance
toxicity
Molecule
two or more atoms held together by chemical bonds in a certain spatial arrangement
Isotope
two or more forms of the same element (same number of protons) whose atoms differ in number of neutrons, and hence in mass
parts per million
unit of concentration 10,000 times smaller than 1% (one part per hundred)
Groups
vertical columns in the periodic table that organize elements according to important properties that they have in common and are numbered from left to right
Tragedy of the commons
when a resource is common to all and used by many, but has no one in particular responsible for it. As a result, the resource may be destroyed by overuse to the detriment of all who use it
nitrogen monoxide, responsible for ozone destruction
•NO
hydroxyl
•OH
We get two bands of hits by throwing a marble, and an interference pattern of many bands with a wave.
According to Dr. Quantum, what do you get when you throw marbles through slits? What do you get when you push a wave through two slits?
Electrons exist in orbitals with a specific energy and probability density in space.
According to the quantum mechanics model, electrons exist where and with what two things?
liquid and solid particles that remain suspended in air rather than settling out
Aerosol
highly reactive metals with one outer electron
Alkali metals
reactive metals with two outer electrons
Alkaline earth metals
Yes, but it will take a very long time for the atmospheric chlorine levels to decrease
Are the treaties made under the Montreal Protocol and its revisions working?
Natural sources, like sea water and volcanoes, but they're all water-soluble. They get washed out in rain before they have an opportunity to destroy ozone
Aside from CFCs, where else does the chlorine implicated in stratospheric ozone come from?
The amount of radiation emitted from the Sun changes over an 11- to 12-year cycle related to sunspot activity, which also mildly affects O3 production
Aside from Earth angle and distance from the Sun, what can vary the amount of radiation from the Sun?
cataracts, retinal damage
Aside from skin damage, what other damage does UV radiation incur?
wind patterns in the stratosphere
Aside from the Sun, what else can affect ozone concentrations?
the free radical •NO, nitrogen monoxide
Aside from water molecules and their breakdown products, what are the other free agents responsible for natural ozone destruction?
at the equinox (March and October), when the Sun is directly overhead
At the equator, when does the period of highest radiation intensity occur? Why?
2 ppb
At what level of stratospheric chlorine did the Antarctic ozone hole appear?
Visible
At what wavelength is the greatest intensity of radiation emitted?
number of protons in the nucleus of an atom
Atomic number
2C8H18 + 25O2 16CO2 + 18H2O
Balance C8H18 + O2 CO2 + H2O.
...
Balance CH4 + O2 CO2 + H2O.
chemical substance that participates in a chemical reaction and influences rate without itself undergoing permanent change
Catalyst
reduce carbon monoxide in the exhaust stream by catalyzing the combustion of CO to CO2 and lower NO2 emissions by catalyzing conversion back to N2 and O2
Catalytic converters
the first set of natural steady-state reactions proposed for stratospheric ozone
Chapman cycle
process whereby substances described as reactants are transformed into different substances called products
Chemical reaction
compounds composed of elements chlorine, fluorine, and carbon (but don't contain element hydrogen)
Chlorofluorocarbons
compounds composed of the elements chlorine, fluorine, and carbon (but do not contain the element hydrogen)
Chloroflurocarbons
chemicals added to soften latex particles in paint so that these particles spread to form a continuous film of uniform thickness
Coalescent
Comes as a byproduct of coal combustion, but its production levels have severely dropped off in recent decades.
Describe mercury emission over time and from where.
Heavy metal that doesn't stay in air long, but can travel long distances in the troposphere
Describe mercury.
8% is UV, 39% is visible, and 53% is IR
Describe the amount of energy each part of the electromagnetic spectrum provides from the sun.
Log scale, biological sensitivity on Y-axis, wavelength (nm) on x-axis
Describe the biological sensitivity graph for UV.
O2 + UV photon of less than 242nm 2O, and O2 + O O3
Describe the creation portion of the Chapman cycle.
O3 + UV photon of less than 320 nm O2 + O. O3 + O 2O2
Describe the destruction portion of the Chapman cycle.
World Plan of Action on Ozone Layer in 1977 to guide future international actions, Vienna Convention on Protection of Ozone Layer in 1985 to protect ozone layer and do research, Montreal Protocol of Substances That Deplete Ozone Layer in 1987 agreeing to limit CFC production
Describe the global response to ozone depletion.
Vienna Convention on the Protection of the Ozone Layer in 1985, Montreal Protocol on Substances that Deplete the Ozone Layer (1987), follow up meetings in the 90s, and meetings in the 2000s to phase out other ozone-depleting chemicals
Describe the policy response to ozone depletion.
The orbital for the one-electron H atoms is spherical...other atoms have electron orbitals with different shapes.
Describe the shape of electron orbitals.
The atomic radius gets steadily larger and larger, with group 1A and 2A's atoms' radius larger than those in the other groups
Describe the trends you see in the periodic table regarding an atom.
NO2—sunlightNO+0, then O+ O2 O3
Describe with two chemical equations how NO2 becomes O3.
1 out of 6700 hydrogen atoms, contains a neutron in the nucleus
Deuterium
...
Draw the Lewis structures of ozone.
10 times the value corresponding to the mark immediately below it on the axis
Each mark on the y-axis of biological sensitivity represents what compared to the value of the mark immediately below it on the vertical axis?
...
Filament lamp and helium tube.
Energy of radiation and the sensitivity of the organism
For animals and plants, what do the effects of UV radiation depend primarily? Two things.
highly reactive chemical species with one or more unpaired electrons
Free radical
CCl3F
Freon-11
CCl2F2
Freon-12
6.02*10^23
Give Avogadro's number.
reactive nonmetals with 7 outer electrons
Halogens
inert, nontoxic compounds that contain chlorine or fluorine (or both, but no hydrogen). But in addition, they contain bromine
Halons
they don't appear naturally; they're made by humans
How are chlorofluorocarbons formed?
scientific notation
How are concentrations expressed?
parts per million or as micrograms per with micrometers
How are concentrations usually expressed?
They are arranged in certain energy levels. The electrons in the innermost level are most strongly attracted by the positively charged protons in the nucleus. The greater the distance between the electron and the nucleus, the weaker the attraction between them
How are electrons arranged around the nucleus?
those with similar chemical properties fall into the same column (group)
How are elements arranged in the periodic table aside from atomic number?
Bromine undergoes a similar reaction to CFCs by acting as a catalyst in a cycle, but it is even MORE effective at destroying O3
How are halons implicated in ozone destruction?
nitrogen and oxygen are found as molecules, whereas argon is found as an atom
How are nitrogen, oxygen, and argon found in the air (in terms of structure)?
As sunlight warms the stratosphere, the polar stratospheric clouds dissipate, halting the chemistry that occurs on surfaces of ice crystals. Then air from lower latitudes flows into polar region, replenishing depleted ozone levels. By end of November, hole is largely refilled.
How are ozone levels replenished in the Antarctic?
500 mL
How big is an average breath?
1) Note number of outer electrons contributed by each of the atoms, 2) Add the outer electrons contributed by the individual atoms to obtain the total number of outer electrons available, 3) Arrange the outer electrons in pairs, then distribute them as to maximize stability by giving each atom a share in enough electrons to fully fill its outer level: 2 electrons in the case of hydrogen, 8 electrons for most other atoms
How can Lewis structures be predicted? 3 steps.
Use planck's equation, where E=hν
How can we quantify light?
Measuring the amount of UV radiation reaching a detector; the lower the intensity of the radiation, the greater the amount of ozone in the column
How can you determine the amount of ozone in a vertical column of air of known volume?
constituted of individual bundles of energy called photons
How did Albert Einstein argue radiation should be viewed?
Chemical formulas show the types and ratio of atoms present. In contrast, Lewis structures also indicate how the atoms are connected and show the nonbonding pairs of electrons, if present.
How do Lewis structures and chemical formulas differ?
they are the only gases
How do chlorine and fluorine differ from the other halogens?
Air pollutants come from chemical reactions, whereas indoor pollutants are emitted by substances
How do outdoor and indoor pollutants differ?
...
How do you calculate the number of CO molecules in a breath?
when you remove the nonbinding electrons from the Lewis structure
How do you make a structural formula from a Lewis structure?
sulfur dioxide reacting with oxygen in air
How do you make sulfur trioxide?
UV photon (less than 220 nm) breaks up CCl2F2 into CClF2 and Cl. The Cl free radical pulls an oxygen atom away from an O3 molecule to form ClO (chlorine monoxide) and an O2 molecule. Two ClO molecules combine to make ClOOCl. UV photons break ClOOCl apart into ClOO and Cl, and ClOO decomposes a second time into Cl and O2.
How does CFC destroy stratospheric ozone? Long form.
by catalyzing the combustion of CO to CO2
How does a catalytic converter reduce CO emission?
by catalyzing conversion back to N2 and O2
How does a catalytic converter reduce NO2 emission?
8.4x102+2=8.4x104L=84 m3
If there are a hundred students in class, how much does the class breathe in one hour?
21 would be oxygen molecules, 78 would be nitrogen molecules, and 1 would be an argon atom
If you look at a sample of 100 of the molecules and atoms in the air, how many would be of each element?
Bromine-containing halons because halons are even more effective than CFCs in harming the ozone layer
In addition to CFCs, what else did the Montreal Protocol try to phase out? Why?
A particle
In addition to being a wave, what else is light?
Relationship among composition, molecular structure, boiling point, and proposed use
In addition to toxicity, flammability, and stability, what three other things must be considered for a CFC substitute?
the atom with the single atom
In molecules like water that have a single atom bonded to two more atoms of a different element(s), what is the central atom in the structure?
840L of air
In one hour, how much does one person breathe?
water products, nitrogen oxide, and other naturally occurring compounds
In terms of natural causes of ozone depletion, what are the main offenders?
It forms in the presence of sunlight from other pollutants in the atmosphere. Once the sun goes down, the generation of ozone ceases, and any present ozone quickly reacts with something else and disappears
In the troposphere, how and when does ozone develop?
percentages based on volume or in terms of the numbers of molecules and atoms present
In what two ways can you describe the composition of the atmosphere?
Reduced mass reduces the boiling point, which is undesirable for a refrigerant
Introducing hydrogen atoms in place of halogen atoms in CFC substitutes reduces total mass. What is the consequence of this?
representation of an atom or molecule that shows its outer electrons
Lewis structure
Resonance forms
Lewis structures that represent hypothetical extremes of electron arrangements in a molecule
v = c/λ. λ = 600nm = 600 *10^-9 = 6.00 * 10^-7. So, v = c/λ, so (3.00 * 10^8ms^-1)/(6.00*10^-7) = 0.500*10^15 = 5.00 * 10^14s^-1
Light in the red region of the visible spectrum has a wavelength of 600 nm. What is the frequency of this light? What are the units?