Atmosphere- 2 Air pollution

Question 1

What must happen with the reactants when a chemical reaction occurs?

Answer 1

Come together
In correct orientation
Enough energy (activation energy)

Question 2

What does activation energy lead to?

Answer 2

temperature dependence

Question 3

What happens to most reactions as they get hotter?

Answer 3

Get faster

Question 4

Where does the energy come from for photochemical reactions?

Answer 4

Sunlight

Question 5

What are thermal reactions driven by?

Answer 5

energy possessed by reactants

Question 6

How do you calculate the rate of change of concentration?

Answer 6

Rate Law x stoichiometry

Question 7

What does stoichiometry tell us?

Answer 7

relative numbers of reactant and product species destroyed / created per reactive
encounter

Question 8

What does the rate of a chemical reaction tell us?

Answer 8

the rate of change of concentration of reactants or products

Question 9

What does Rate Law tell us?

Answer 9

how/what the rate depends on

Question 10

What is the rate of reaction like for an elementary reaction?

Answer 10

proportional to concentration of all reactants

Question 11

What is the equation for temperature/ temperature dependence?

Answer 11

k= A exp (-Ea / RT)

Question 12

What do the letters in the temperature dependence equation mean?

Answer 12

A= pre-exponential factor
Ea= activation energy (Joules per mole)
R= Gas constant
T= temp in Kelvin

Question 13

What will the equation be like if there is positive temperature dependence?

Answer 13

Ea is positive
Rate constant increases with higher temp

Question 14

What will the equation be like if there is negative temperature dependence?

Answer 14

Ea negative
Rate constant decreases with higher temp

Question 15

What has happened to air quality in the UK since 1950’s?

Answer 15

substantially improved

Question 16

How does the UK’s current air quality affect the life of the human population?

Answer 16

34,000 deaths/yr
4-6 month life expectancy reduction

Question 17

What is the economic cost per year of the air quality?

Answer 17

£20bn

Question 18

How many global deaths are there resulting from air quality per year?

Answer 18

8 million

Question 19

How much of people living in urban areas live with air quality worse than WHO guidelines?

Answer 19

80%

Question 20

What does ground level cause significant damage to?

Answer 20

plants

Question 21

How does ozone damage plants?

Answer 21

enters the leaf through stomata, and attacks cell membranes, reducing plant health & growth / yield

Question 22

What losses does ozone have on global crop yield?

Answer 22

5-12%

Question 23

What are 2 key air pollutants?

Answer 23

NOx
Fine particles (PM2.5)

Question 24

What are the sources of NOx?

Answer 24

Local road traffic (60%)
Road traffic background (18%)
Homes, industry and commerce (9%)
Regional background (8%)
Non-road transport and mobile machinery (5%)

Question 25

What is the make up of the local road traffic source of NOx?

Answer 25

Biggest is diesel cars with other diesel vehicles being the biggest contributors

Question 26

When a NOx concentration map is put of the west midlands what image do you get?

Answer 26

highest concentration map out road systems

Question 27

How does concentration of NO2 change throughout the day?

Answer 27

Peaks when there is both rush hours (UoB peak later as people work till later at uni)

Question 28

What are some of the sources of PM2.5?

Answer 28

Road traffic Power generation Aircraft Agriculture Shipping Home (cooking) Industry

Question 29

What does the longer lifespan of PM2.5 mean?

Answer 29

areas will all have similar concentrations thus concerted local, regional and national action needed

Question 30

What type of pollutant is ozone?

Answer 30

secondary pollutant formed in atmosphere

Question 31

What is the formula for the formation of ozone?

Answer 31

VOC + NOx + sunlight = Ozone (O3)

Question 32

Why can ozone be a transboundary pollutant?

Answer 32

VOC and NOx emissions might be quite far upwind

Question 33

What is the formation timescale of ozone?

Answer 33

days-weeks

Question 34

What is ozone formation exacerbated by?

Answer 34

fine weather Sunshine Airmass from Europe (UK formation)

Question 35

What are the UKs air quality objectives for NOx and PM2,5?

Answer 35

NOx= 40 ug/m3 - Annual Average PM2.5= 10 ug/m3 Annual Average, by 2040

Question 36

What are the WHO guidelines for NOx and PM2.5?

Answer 36

NO2= 10 ug/m3 Annual average PM2.5= 5 ug/m3 Annual average

Question 37

What has Birmingham done to reduce NO2?

Answer 37

Created the bham clean air zone Offending cars- £8 per day HGV- £50 per day