O3 formation/depletion

Question 1

what is ozone

Answer 1

3 allotropic O atoms, is highly reactive and a powerful oxidizer

Question 2

what is UV-A

Answer 2

UV at 315-400 nm - 7% of sun (no harm)

Question 3

what is UV-B

Answer 3

UV at 280-3115nm - 1.5% of sun (long term exposure harm)

Question 4

what is UV-C

Answer 4

UV at <280nm - 0.5% of sun (extreme harm)

Question 5

is ozone good at blocking UV-B rays?

Answer 5

no it doesn’t absorb the right wavelength to block UV-B

Question 6

what type of Thymine dimers are there

Answer 6

T+T, T+C

Question 7

Where is the ozone layer

Answer 7

in the stratosphere 23km above the Earth

Question 8

How should O3 be measured

Answer 8

measured with laser A (308nm absorbable) and laser B (351nm unabsorbable) and the difference is the contration seen

Question 9

what is Dobson unit

Answer 9

amount of ozone needed to cover 0.01mm on the Earth’s surface @0.0C (1DU = 0.01mm)

Question 10

what is the average DU for ozone

Answer 10

300 DU

Question 11

what is the Du at the poles

Answer 11

450 DU

Question 12

what is the Du at the equator

Answer 12

220 DU

Question 13

When is the ozone hole a great concern

Answer 13

when the DU is below 220DU (lowest is 85DU)

Question 14

what are the seasonal ozone changes

Answer 14

higher in fall/winter - no tress to absorb
lower in spring/summer - photosynthesis happening

Question 15

what does sunscreen protect from

Answer 15

UV-B

Question 16

what does SPF stand for

Answer 16

sun protection factor: how much UV-B is blocked

Question 17

how is SPF measured

Answer 17

15 SPF mean you can stay that much longer in the song

Question 18

what are CFCs and what were they used for

Answer 18

there are chlorofluorocarbons from the 1930s it was used as a refrigerant in fridges and ACs

Question 19

what is Feron

Answer 19

it is a patented CFC

Question 20

disadvantages of CFC

Answer 20

heavy into troposphere, they go through photolytic decomp (Cl radicals are bad)

Question 21

what is ODP

Answer 21

amount of ozone depletion

Question 22

ODP formula

Answer 22

1kg of chem comparison/1kg of CFC-11

Question 23

what don’t F radicals form readily in the atmosphere

Answer 23

because are smaller and closer means holding onto there e-

Question 24

advantages of HCFCs/HCFs

Answer 24

lower ODP, lower lifetime, replaces CFCs

Question 25

disadvantages of HCFs/HCFs

Answer 25

acidic, toxic, slower ozone depletion, expensive, flammable

Question 26

what are halons and where are they used

Answer 26

are bromide analogues and are used in fire extinguishers

Question 27

halon advantages

Answer 27

higher density, terminates radical chain rxn that start combustion rxn

Question 28

halon disadvantages

Answer 28

more ozone depletion readily, high lifetime

Question 29

Montreal protocol

Answer 29

international agreement to eliminate substances depleting the ozone layer