Quiz 1 Matterial

Question 1

1 Dobson Unit DU is equivalent to how many cm?

Answer 1

0.001

Question 2

1 Dobson Unit DU is equivalent to how many mm?

Answer 2

0.01

Question 3

Spacial distribution of ozone in the Arctic

Answer 3

~450-550 DU

Question 4

Spacial distribution of ozone in the temperate

Answer 4

~300-375 DU

Question 5

Spacial distribution of ozone in the tropics

Answer 5

~225-250 DU

Question 6

Spacial distribution in the ozone hole

Answer 6

~150 DU

Question 7

UV light range for UVA

Answer 7

320-420 nm

Question 8

UV light range for UVB

Answer 8

280-320 nm

Question 9

UV light range for UVC

Answer 9

200-280 nm

Question 10

How much UV is removed by O2

Answer 10

Most of UVC

Question 11

How much UV is removed by O3

Answer 11

All of UVC and most of UVB

Question 12

How much UV makes it to earth

Answer 12

All of UVA and some of UVB

Question 13

rxn 1: O2—->O+O

Answer 13

+Delta H
Endothermic
Photo-chemical
How O3 is formed

Question 14

rxn 2: O2+O—>O3+Heat

Answer 14

-Delta H
Exothermic
How O3 is formed

Question 15

rxn 3: O+O—>O2+Heat

Answer 15

Removes an O that could have formed O3 by reaction 2
-Delta H
Exothermic

Question 16

rxn 4: O3—>O2+O

Answer 16

How O3 protects us from UV
O2 is formed and can produce another O3 via rxn 2
How O3 is destroyed
+Delta H
Endothermic
Photochemical

Question 17

rxn 5: O3+O—>2O2

Answer 17

Does not happen much and requires high energy impact
+Delta H 18kJ/mol
endothermic
How O3 is destroyed

Question 18

Regions of the Atmosphere: Stratosphere

Answer 18

Temp increases with increasing altitude (-56 to -2 Celsius)
Stratified
Rxn 2 &3 related to O3 are exothermic and cause temp trend
Altitude 16-50 km

Question 19

Regions of the Atmosphere: Tropopause

Answer 19

Where temp vs altitude trend changes
-56 Celsius
Altitude 10-15 km

Question 20

Regions of the Atmosphere: Troposphere

Answer 20

Temp decreases with increasing altitude
Well mixed except H2O
IR from surface of earth releases heat
25 to -56 Celsius
Altitude 0-9 km

Question 21

Regions of the Stratosphere: Upper

Answer 21

Very thin air
Few molecules
High UV light intensity
Main form of the element oxygen is O
No O2 for rxn 2 therefore no O3 is produced
Most likely fate of O is to hit another O

Question 22

Regions of the Stratosphere: Mid

Answer 22

This air but denser than upper
Less intense UV but still some
Main form of oxygen is O2
Most likely fate of O is to hit an O2 molecule
Rxn 2 happens in this zone so it is the max zone of O3 producation

Question 23

Regions of the stratosphere: Lower

Answer 23

Air more dense
No UVC needed to produce O via O2->O+O
No O
No O2+O->O3
No O3 formation

Question 24

Mechanism I

Answer 24

Step I: X+O3—>OX+O2
Step II: OX+O—>X+O2
Net Rxn: O3+O—>2O2

Question 25

Mechanism II

Answer 25

Step I: O3+X--->OX+O2 Step II: O3+X--->OX+O2 Step III: OX+OX--->X+X+O2 Net Rxn: 2O3--->3O2

Question 26

Natural X Catalysts

Answer 26

Nitric Oxide (NO) and Hydroxyl Radical (HO)

Question 27

Natural X Catalyst Nitric Oxide (NO)

Answer 27

From soil bacteria From lightning Gets rained out Destroys O3 via mechanism II

Question 28

Natural X Catalyst Hydroxyl Radical (HO)

Answer 28

Produced everywhere Destroys O3 via mechanism I & II Most overall important natural X catalyst

Question 29

Active forms of Cl

Answer 29

Cl, ClO, 2Cl

Question 30

Deactivated forms of Cl

Answer 30

HCl, ClONO2, Cl

Question 31

Activation rxns

Answer 31

OH+HCL--->H2O+Cl ClONO2--->ClO+NO2 Cl2--->2Cl

Question 32

Deactivation rxns

Answer 32

Cl+CH4--->HCL+CH3 ClO+NO2--->ClONO2

Question 33

Five steps for Atlantic Ozone whole formation

Answer 33

1) South pole winter conditions 2) Temperature drop vortex forms 3) Polar stratospheric cloud formation (PSC) 4) Light reappears 5) Deactivation

Question 34

Atlantic Ozone whole formation step 1

Answer 34

No sun Therefore no O2--->O+O So no O3 production No heat from O+O2--->O3 Therefore very cold -80 celsius

Question 35

Atlantic Ozone whole formation step 2

Answer 35

Decrease in Temp Low pressure system forms vortex forms 300mph Isolates airmass no O3 production

Question 36

Atlantic Ozone whole formation step 3

Answer 36

Net rxn ClONO2+HCl--->HNO3+Cl2

Question 37

Atlantic Ozone whole formation step 4

Answer 37

Cl2--->2Cl activated Chlorine Mechanism I or II destroys O3

Question 38

Atlantic Ozone whole formation step 5

Answer 38

Temp increases PSC melt above -80 celsius HNO3 from PSC Mechanism I O3 recovers

Question 39

CFC Replacements

Answer 39

C2HF5, CH2FCF3, C2H4F2, blends of C2H3F3 and CH2F2

Question 40

CFC Replacements C2HF5

Answer 40

Refrigerants and Fire fighting Lifetime 29 Years

Question 41

CFC Replacements CH2FCF3

Answer 41

Air conditioners Inhalers Fire suppressants foam blowing Lifetime 9.6 years

Question 42

CFC Replacements C2H4F2

Answer 42

Spray cans lifetime 1.4 years

Question 43

Primary Pollutants

Answer 43

Car exhaust Power Plants Natural sources

Question 44

Secondary Pollutants

Answer 44

Transformation products produced by photo-chemical reactions e.g organic compounds, O3, HNO3

Question 45

Smog

Answer 45

A mix of O3, organic compounds, HNO3 Produced by photochemical reactions VOC's+NOx--->organic compounds+HNO3+O3

Question 46

Conditions favorable for smog

Answer 46

Traffic Sunlight and warm temps Stagnant air mass (warm over cold) usually caused by mountains

Question 47

Smog timeline

Answer 47

8am NO up 12 NO2 up 5pm HNO3 and O3 up organic compounds from photochemical reactions rise throughout the day VOC's rise till late morning then fall off through the rest of the day

Question 48

1st catalytic converters on cars in the 70s

Answer 48

Run carburetor fuel RICH excess fuel Use up all O2 so no NOx production VOCs released from engine get oxidized in catalytic converter

Question 49

2nd Catalytic converters on cars in the 80s

Answer 49

Run carburetor fuel LEAN excess O2 Use up all fuel so no VOC release NOx produced in engine gets reduced in catalytic converter

Question 50

General Bond energy rule

Answer 50

Stronger energy bond wins