2.4.1 Chemistry of the Air

?
which bonds absorb infrared radiation? where are these bonds found?
C=O/ O-H/ C-H - found in CO2/ H2O/ CH4
1 of 19
What does the Greenhouse effect of a gas depend on?
atmospheric concentration / ability to absorb IR / residence time
2 of 19
What is global Warming?
warming of the planet due to increased conc. of greenhouse gases in the troposphere, which enhances the the greenhouse effect
3 of 19
What is causing global warming?
methane levels increasing as more cows / paddy fields / burning fossil fuels / chopping down trees
4 of 19
what are the consequences of global warming?
increased sea levels / land lost / flooding / stormier less predictable weather / less rainfall - crop failures - famine / diseases
5 of 19
what roles are chemists playing in minimising climate change?
provide scientific evidence to governments to verify / monitor atmosphere changes / analyse sea samples // investigate solutions to environmental problems (CCS) // monitor progress against initiatives such as Kyoto
6 of 19
what is CCS?
carbon capture and storage // removal of CO2 as a liquid and inject into sea beds of deep oceans // react CO2 with metal oxides to form stable solid carbonates
7 of 19
what is the ozone layer?
naturally occurring region of the atmosphere which has a high conc. of ozone and protects earth from UV radiation
8 of 19
what is lower atmosphere ozone?
smog - pollutants
9 of 19
What state is O3 in?
continuously being formed and broken down in the stratosphere by UV radiation - is in eqm
10 of 19
how is O3 formed?
when UV from the sun's radiation is absorbed by O2 it splits into 2.O // free radicals combine to form O3
11 of 19
how is O3 destroyed?
UV / O3 + UV --> O2 + O.
12 of 19
How does ozone protect us?
frequency of UV absorbed is the same as damaging UV / filters out all UVC and 90% UVB / allows life eon earth / skin cancer / premature raging / needed for vitamin D
13 of 19
What is causing the destruction of the ozone?
CFCs - chlorine free radicals formed when C-Cl bond broken by UV / NOx from air craft engines/ thunder EQUATIONS
14 of 19
How is the destruction of the ozone being managed?
Legislation to ban CFCs / HCFCs developed / CFCs still entering atmosphere from disused items / still used / long lifetime in atmosphere
15 of 19
What pollutants do internal combustion engines produce?
nOx - formed when N2 in the air reacts with high temps and sparks // CO // CO2 // unburnt hydrocarbons // soot
16 of 19
what are the environmental consequences of the pollutants produced by internal combustion engines?
NOx - toxic/depletes O3 // CO - toxic // CO2 - global warming // unburnt H.Carbons - photochemical smog // soot - global dimming and respiratory problems
17 of 19
what do catalytic converters do?
remove CO, NOx and unburnt H. Carbons from exhaust gases turning them into harmless CO2, N2 and H2O
18 of 19
how do catalytic converters work?
CO/NO absorbed onto surface of catalyst / weakens bonds in CO and NO lowering Ea / reaction occurs / CO2 and N2 desorbs from surface / catalyst platinum used
19 of 19

Other cards in this set

Card 2

Front

What does the Greenhouse effect of a gas depend on?

Back

atmospheric concentration / ability to absorb IR / residence time

Card 3

Front

What is global Warming?

Back

Preview of the front of card 3

Card 4

Front

What is causing global warming?

Back

Preview of the front of card 4

Card 5

Front

what are the consequences of global warming?

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Chemistry resources:

See all Chemistry resources »See all Green Chemistry resources »