Exam 1 Flashcards
1
Q
Composition of Air Inhaled
A
Nitrogen 78% Oxygen 21% Argon 0.9% Carbon Dioxide 0.04% Water Vapor - variable
2
Q
Composition of Exhaled Air
A
Nitrogen 78% Oxygen 16% Argon 0.9% Carbon Dioxide 4.0% Water vapor - variable
3
Q
Criteria Pollutants (5)
A
- Carbon Monoxide
- Ozone
- Sulfur Dioxide
- Nitrogen Dioxide
- Particulate Matter
4
Q
Carbon Monoxide
A
- silent killer
- interfers with ability of hemoglobin to carry oxygen
Effects:- dizzy, headache, nauceous
Sources: - automobiles, charcoal grills, propane camping stoves
- dizzy, headache, nauceous
5
Q
Ozone
A
- sharp odor
- can reduce lung function even at low concentrations
- can destroy crops and pine needles
Symptoms:- chest pain, coughing, sneezing or lung congestion
Sources: - seconday pollutant (VOCs and NO2 and sunlight)
- chest pain, coughing, sneezing or lung congestion
6
Q
Sulfur Dioxide
A
- unpleasant odor
- dissolves in moist tissues of lungs to form an acid
- young and elderly especially at risk
Symptoms:- respritory distress, heart failure, asphyxiation, lung damage
Sources: - burning coal
- respritory distress, heart failure, asphyxiation, lung damage
7
Q
Nitrogen Dioxide
A
- brown color
- dissolves in lungs to produce an acid
SOURCE:- secondary pollutant (comes from NO which comes from anything hot including engines, and coal fired power plants) also from in grain silos
8
Q
Particulate Matter
A
- mix of solid an liquid droplets
- least understood of the air pollutants
- classified by size
- smaller = more harmful
SOURCE:- vechile engines, coal burning power plants, wildfires, and blowing dust
- soot and smoke
- construction and mining sites
- compound ammonia used in agriculture
9
Q
The process of evaluating scientific data and making predictions in an organized manner about the probabilities of an outcome
A
Risk Assessment
10
Q
How risk assessment is calculated for a substance
A
Toxicity and Exposure
11
Q
The intrinsic health hazard of a substance
A
Toxicity
12
Q
The amount of the substance encountered
A
Exposure
13
Q
Factors that exposure depends on
A
1) Concentration in the air
- more toxic the pollutant the lower its concentration
2) Length of time
3) Rate of breathing
14
Q
Which act led to the establishment of air quality standards?
A
US Clean Air Act 1970
15
Q
Act that focuses on preventing the formation of hazardeous substances
A
Pollution Prevention Act (1990)
16
Q
National standard for the AQI
A
100
17
Q
Colors for good to moderate air quality
A
green/yellow
18
Q
Colors for unhealthy air quality
A
red/purple/maroon
19
Q
A set of key ideas to guide all in the chemical community. “Benign by design”
A
Green Chemistry
20
Q
A pure substance made up of one type of element
A
Element
21
Q
A pure substance made up of two or more different elements in a fixed, characteristic chemical composition
A
Compound
22
Q
Who invented he periodic table
A
Dmitri Mendeleev
23
Q
Elements that are shiny and conduct electricity and heat well (green area in periodic table)
A
Metals
24
Q
Elements that do not conduct heat or electricity well and have no one characteristic appearance (light blue)
A
Non Metals
25
Fall between metals and non metals only 8 on the periodic table
Metalloids
26
Vertical columns in periodic table are called
Groups
27
Reactive metals in group 7A are called
Halogens
28
Non reactive gases in group 8A are called
Nobel Gases
29
The smallest unit of an element that can exist as a stable independent entity
Atom
30
Two or more atoms held together by chemical bonds in a certain spatial arrangement
Molecule
31
Molecule consisting of two atoms
Diatomic Molecule
32
Compounds made up only of the element hydrogen and carbon
Hydrocarbons
33
Matter and Mass are conserved in a chemical formula
Law of conservation of matter and mass
34
When all of hydrocarbon atoms in the hydrocarbon molecule combine with O2 molcules from the air to form CO2 and hydrogen atoms combine with O to form water
complete combustion
35
When not enough O2 is in a hydrocarbon reaction and the result is CO created instead of CO2
incomplete combustion
36
Pollutants that come from motor vehicles and coal-fired plants that generate electricity
SO2, CO, NO, and PM
37
Liquid and solid particles that remain suspended in the air rather than settling out.
Aerosols
38
Examples of aerosols
Campfire smoke
| Cigarette Smoke
39
What happens when SO2, and water vapor combine
It helps condense water vapor into an aerosol of tiny water droplets that form sulfuric acid.
40
Act that mandated reductions in sulfur
Clean Air Act
41
Can vehicles emit sulfur dioxide?
No, because internal combustion engines primary fueled by gasoline that has little to no sulfur.
42
Why has there been a reduced amount of CO from exhaust pipes?
Catalytic converters that reduce the amount of CO2 by conversion of nitrogen oxides back to N2 and O2
43
A chemical substance that participates in a chemical reaction and influences its rate without itself undergoing permanent change
Catalyst
44
Substance readily passes into the vapor phase, it evaporates easily examples are gasoline and nail polish remover
Volatile
45
Substances that contain carbon
Organic Compounds
46
Carbon-containing compounds that pass easily into the vapor stage
Volatile organic Compounds (VOCs)
47
VOCs
- can occur naturally and by humans
- pine tree smell
- tail pipe exhaust
- in catalytic converters use oxygen to burn VOCs to form carbon dioxide and water
- form NO2 when break down in the air
- can form by burning candles
48
A designated region in the stratosphere of maximum ozone concentration that protects against harmful UV rays
Ozone Layer
49
Group 1A in the periodic table is called
Alkali metals
50
Group 2A in the periodic table is called
Alkaline earth metals
51
The distance between successive peaks
Wavelength
52
The number of waves passing a fixed point in one second
Frequency (v)
53
Relationship between wavelength and frequency
Inverse (shorter the wavelength higher the frequency)
54
A continuum of waves and ranges from short, high-energy X-rays and gamma rays to long, low0enrgy radio waves
electrogmagnetic spectrum
55
The entire collection of different wavelengths each with its own energy
Radiant energy
56
Order of wave lengths shorter to higher
```
gamma rays
x-rays
UV
Visible
IR
Microwave
Radio
```
57
Amount of energy that comes in as UV, Visible and IR radiation
UV 8%
Visible 39%
IR 53%
58
Is energy distribution continuous?
No, it is quantized think of like steps on a stair case not a ramp
59
Radiation is individual bundles of energy called...
photons
60
Relationship between energy and wavelength
Inverse (as wavelength decreases energy increases)
61
What do short wavelength UV rays do to molecules
Breaks them apart which can create genetic defects and cancer
62
UV rays that are absorbed in the upper atmosphere and never reach the ground
UV-C wavelength (200-280) highest energy splits O2 to 2O
63
Wavelength that can split O3 in atmosphere
anything less than 320 (UV-B and UV-C)
64
A condition in which a dynamic system is in valance so that there is no net change in concentration of the major species involved
steady state
65
Represents the first set of natural stead0state reactions proposed for stratospheric ozone
Chapman Cycle
66
Document that recognized the depletion of ozone in the stratosphere due to human involvement and took steps to reverse this effect.
Montreal Protocol on Substances that Deplete the Ozone Layer
67
How UV rays can harm
- skin damage
- eye damage
- UV-C used to sterilize surfaces and kill bacteria
- can harm marine life such as fish eggs, larva and young fish
68
Dobson Unit Information
- 220DU is considered a hole
| - dark blue and purple regions indicate where lowest concentrations of O3 are observed
69
Natural Ozone Destruction around the Globe
- water evaporates from the oceans and a few molecules reach the stratosphere
-UV rays break water molecules into H. and hydroxyl .OH free radicals
- the free radicals convert O3 to O2
(the same thing can happen with N2O when it breaks down into .NO, N2O is produced in soils and oceans by microorganisms)
70
Compounds composed of the elements chlorine, fluorine, and carbon (but don't contain hydrogen) which are highly unreactive that are human synthesized.
chlorofluorocarbons (CFCs)
71
First reason CFCs were used
For refrigerators because highly unreactive, than later fire suppressants, and air conditioning.
They are cheap.. nontoxic, nonflammable, and widely available
72
How long does CCl2F2 (CFC) remain in the atmosphere before decomposing
120 years
73
Problem with CFC's in the atmosphere
- UV-C breaks down CFC so free radical chlorine is released.
- Cl. free radical pulls an oxygen atom away from an O3 to form ClO.
- 2 ClO. -> ClOOCl
- ClOOCl --uv-photon--> ClOO. + Cl
- ClOO. -> Cl. + O2
net equation 2 O3 -> 3 O2 (pg 104)
74
Theory that as ozone decreases chlorine increases in the stratosphere
Rowland-Molina hypothesis
75
Reason for hole in the ozone layer in the arctic
- In June-Sep winds circulate around the South Pole form a vortex that prevents warmer air from entering the region
- temp drops to -90C
- polar stratospheric clouds (PSCs) can form made of tiny ice cryctals
- chem reactions occur on the surface of the ice crysals
- in sep more sunlight creates the chlorine based atoms to split
76
How to measure the positive affect on the removal of CFC's on Ozone
Noticing the decrease in the amount of effective stratospheric chlorine peaked in 1990s and is now decreasing
77
Replacement for CFC's resulting in a substitution of one Cl atom for a H atom
Hydrochlorofluorocarbons (HCFC)
78
Problems with hydrochloroflourocarbons
- increases in flammability
- decreases in boiling point (results in re-engineering)
- still has a Cl atom
- scheduled to be phased out by 2030
79
Positives with hydrochloroflourocarbons
- atmospheric lifetime of only 12 yrs compared to 110 for CFC-12
- mostly breaks down in the lower atmosphere and hardly reaches the stratosphere
80
Replacements for HCFCs that only contain hydrogen, fluorine, and carbon (no more chlorine)
Hydroflourocarbons (HFCs)
81
Positives of HFCs
Does not deplete stratospheric ozone
| has a short atmospheric lifetime
82
Problems with HFCs
They are green house gases
| Absorb infrared radiation and trap heat in the atmosphere (similar to carbon dioxide)
83
New gases that could replace HFCs
- hydroflouroolefins (GWP very low, shorter atmospheric lifetime)
- CO2
- propane
84
How cold would the earth be without the green house effect?
- 18C
| - 0F
85
IR radiation absorption, reflection and emission
- 46% absorbed by earth
- Earth reemits all of the radiation it absorbs but at a longer wavelength (less energy)
- 9% of remmited goes to space
- 37% remitted and absorbed in the atmosphere
- 54% of sun's radiation is absorbed by the atmosphere (23%) reflected from the atmosphere (25%) or reflected from the earth's surface (6%)
86
Percentage of radiation absorbed by the atmosphere
Directly from sun (23%)Earth's surface (37%)
| all eventually emitted into space to complete the energy balance
87
percentage of earth's emitted radiation which will be absorbed in the atmosphere
80%
88
The natural process by which atmospheric gases trap a major portion (about 80%) of the infrared radiation radiated by the Earth
green house effect
89
Earth's annual temp
15C or 59F
90
Gases capable of absorbing and emitting infrared radiation, thereby warming the atmosphere
Greenhouse gases
91
List of greenhouse gases
```
carbon dioxide
water vapor
methane
nitrous oxide
ozone
chlorofluorocarbons
```
92
The process in which atmospheric gases trap and return more than 80% of the heat energy radiated by the Earth
Enhanced Greenhouse Effect
93
Term used to describe the increase in average global temperature that result from an enhanced greenhouse effect
Global Warming
94
Natural greenhouse gas sources
Sun IR
| Volcanic eruptions
95
How to find out CO2 composition of air long ago
Air bubbles trapped in ice
- can see periodic cycles
- can see CO2 concentration is about 100ppm higher than any time in the last million years
- ratio of 2H to 1H can be measured and used to estimate the temperature at the time the snow fell. (richer in 2H means warmer??)
96
Greenhouse gases
Carbon dioxide, water, and methane
97
Why are oxygen and nitrogen not greenhouse gases
Their shape does not allow them to vibrate in the same way
98
What structure diagram lines stand for (wedge, dotted, straight)
wedge - coming out of the paper in the direction towards the reader
dashed- represents a bond pointing away from the reader
solid - in the plane of the paper
99
Shape of the molecude is described in terms of its arrangement of...
atoms
100
Do all molecules absorb IR radiation
No, different molecules absorb IR radiation at different wavelengths and thus vibrate at different energies depending on their molecular structure
101
Is more energy required to stretch or bend a bond
stretch (need IR with shorter wavelengths and more energy)
102
What instrument is used to find infrared (heat) energy that molecules can absorb
infared spectrometer
103
Ways that molecules can absorbed IR
- some hold extra energy for a brief time and then readmit in all directions as heat
- others collide with atmospheric molecules like N2 and O2 and transfer some heat
104
Does the overall electric charge distribution change during molecular vibrations
No
105
3 places you can find carbon
atmosphere
carbon containing rocks
plants and animals
106
3 things to know about the carbon cycle
1. carbon is found in many places
2. carbon is on the move
3. where carbon ends up matters
107
Human sources of CO2 emissions
```
Power and heating
transportation
deforestation
industry
residential/ commercial
7.5 Gt per year
```
108
How we know fossil fuels is main source of CO2 emissions
Isotope C-14 is not present when fossil fuels are burned. Due to a decrease in the presence of C-14 in the atmosphere it is evident that fossil fuels are major source of CO2 emissions.
109
The mass (in grams) of the same number of atoms that are found in exactly 12 g of carbon-12
atomic mass
110
The number of atoms in exactly 12 g of C-12
Avagdro's number
111
Defined as containing an Avagadro's number of objects (used to communicate the number of atoms, molecules or other small particules present)
Mole (mol)
112
The mass of Avagadro's number or one mole of whatever particles are specified
molar mass
113
Characterizes the time required for a gas added to the aatmosphere to be removed "turnover time"
atmospheric lifetime
114
A number that represents the relative contribution of a molecule of the atmospheric gas to global warming
global warming potential (GWP)
115
Sources of Methane
- human and natural
- 40% natural
- wetlands, anaerobic bacteria
- melting in the north
- released from oceans (methane hydrates)
- termites
- human
- agriculture (rice cultivation and livestock)
- landfills
- extraction of fossil fuels (oil and coal deposits)
116
Sources of N2O
```
natural
- bacteria removal of nitrate ion (NO3-) from soilds
- ocean upwellings
-atmospheric interactions of nitrogen compounds and high-energy oxygen molecules
human
- agriculture
- automobile catalytic converters
- ammonia fertilizers
-biomass burnings
- some industrial processes
```
atmospheric life = 120 years
slow but steady rise in the atmosphere
117
Ozone as a greenhouse gas
Creates warming in upper troposphere but a slight cooling effect in the upper stratosphere (depletion of stratospheric ozone is not principle cause of climate change)
118
What did the IPCC (Intergovernmental Panel on Climate Change) at in 2007
- earth getting warmer
- human activities are responsible
- if the rate of greenhouse emissions is not reduced there will be problems
119
The factors (both natural and anthropogenic) that influence the balance of Earth's incoming and outgoing radiation
radiative forcings
120
Describe the different types of radiative forcings
Negative forcings - have a cooling effect (stratospheric ozone, land use, direct effect aersol, cloud albedo effect aersol)
Positive forcings - have a warming effect (solar irradiance(sunspots), black carbon on snow, tropospheric ozone, CH4, N2O, Halocarbons, carbon dioxide)
121
How much of the warming does CO2 constitue for
2/3
122
The ratio of electromagnetic radiation reflected from a surface relative to the amount of radiation incident on it is called (measure of the reflectivity of a surface)....
albedo
| - higher the number the more reflective the surface
123
How albedo decreases
- glaciers and snow melt creating warming
124
How albedo increases
we plant crops that reflect more incoming light than does the dark green foliage of the rain forests causing an increase and then resulting in cooling.
125
Effects of Aerosols
Natural
-dust storms, ocean spray, forest fires, volcanic eruptions
Human
- soot, smoke, and sulfate aerosols
Tiny aerosols are efficient at scattering incoming solar radiation
Some absorb radiation
Create a cooling effect
Serve as nuclei for the condensation of water droplets and hence promote cloud formation
aerosols counter the warming effect of greenhouse gases
complex
126
The daily high and low temperatures, the drizzles and downpours, the blizzards and heat waves, and the fall breezes and hot summer winds that have short durations
Weather
127
Describes regional temperatures, humidity, winds, rains, and snowfall over decades not days
climate
128
Effects of Climate change
- sea ice disappearance
- sea level rise (warm water expands)
- more extreme weather
- changes in ocean chemistry
- loss of biodiversity
- vulnerability of freshwater resources (glacier run-off will disappear)
- human health
129
Any action to permanently eliminate or reduce the long-term risk and hazards of climate change to human life, property, or the enviornment
Climate mitigation (ex. reduce CO2 emissions by decreasing energy consumption)
130
Technology that involves separating CO2 from other combustion products and storing (sequestration) it in a variety of geological locations. Reduces CO2 in atmosphere which would decrease global warming
Carbon capture and storage (CCS)
131
Other was to combat climate change
- reverse deforstation
132
The ability of a system to adjust to climate change to moderate potential damage, to take advantage of opportunites, or to cope with the consequences
Climate adaptation
133
International treaty that legally binded liits on greenhouse gas emissions 1997
Kyoto Protocol
134
What gases were regulated in Kyoto Protocol
CO2. CH4, Nitrous oxide, HFCs, PFCs, and sulfer hexaflouride
135
Problems with US and climate change
Never signed Kyoto protocol
no restriction on CO2 emissions on economic grounds
mitigation measures entail significant up-front costs
