Unit 10 - Chemistry of the environment Flashcards

1
Q

steps to treating water? what do they do? (8 steps)

A

1) screen - filters big particles such as trash
2) coagulant is added - small soluble particles stick together and become insoluble
3) Sedimentation - air is blown through flotation tank to make coagulated particles float to the top (skimmed off)
4) filtration through sand
5) further filtration - charcoal or more sand to get rid of bad smell and taste
6) chlorine - kills bacterias and other microbes
7) fluride - help fight tooth decay
8) water is pumped to storage resevoir - to be pumped into homes

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2
Q

2 water tests? positive result?

A

anhydrous copper sulphate
-white powder –> blue

anhydrous cobalt chloride
-blue –> pink

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3
Q

air components?

A

78% nitrogen
21% oxygen
1% argon + other gases

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4
Q

6 common pollutants? symbols?

A

-carbon dioxide (CO2)
-sulfur dioxide (SO2)
-carbon (C)
-nitrogen monoxide (NO)
-carbon monoxide (CO)
-nitrogen dioxide (NO2)

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5
Q

5 air pollution sources?

A

-combustion of fossil fuels
–> transportation
–> electricity
–> energy (for industry)

-open waste burning (plastic)

-agriculture
–> animal’s burps
–> makes methane (CH4)

-Burning of fossil fuels
–> makes CO2, CO, C, SO2, NO2

-Decomposition
–> makes methane (CH4)

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6
Q

complete combustion formula?

A

CH4 + O2 –> CO2 + H2O

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7
Q

incomplete combustion formula?

A

CH4 –> CO + C

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8
Q

how is nitrogen dioxide made?

A

in internal combustion engines (car engines) as it has high temperature and high pressure and has both nitrogen and oxygen (in air)

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9
Q

effects of solid pollutants?

A

-dust
-carbon
-stops sunlight
–> no vitamin D
–> plants can’t photosynthesis, they die, everything dies

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10
Q

effect of acid rain?

A

-bridges collapse
-lungs have water which react with sulfur dioxide, makes sulfuric acid and melts lungs
-plants and animals get damaged

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11
Q

percentage of oxygen formula?

A

(difference in volume / volume at start) x 100

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12
Q

source of carbon dioxide?

A

-burning of fossil fuels
-respiration
-complete combustion of carbon - containing fuels
-sodium carbonate + HCl
-Thermal decomposition
–> breaking apart something because of acid or heat (1 reactant)

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13
Q

carbon and carbon monoxide source?

A

incomplete combustion of carbon containing fuels

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14
Q

sulphur dioxide source?

A

combustion of fossil fuels (that contain sulfur compounds)

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15
Q

nitrogen oxides source?

A

internal combustion (car engines)

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16
Q

methane source?

A

-waste gases from animal digestion
-decomposition of vegetation

17
Q

fully combusted carbon forms?

A

CO2

18
Q

fully combusted hydrogen forms?

A

H2O

19
Q

carbon monoxide + oxygen?

A

carbon dioxide

20
Q

hydrocarbon + oxygen?

A

carbon dioxide + water

21
Q

nitrogen monoxide + carbon monoxide?

A

nitrogen + carbon dioxide

22
Q

ways to reduce effects of climate change [4]

A

-plant trees
-decrease livestock farming
-decrease fossil fuels burning (use)
-increase use of hydrogen and renewable energy
–> solar panels
–> windmills
–> tidal (waves)
–> geothermal
–> hydrogen powered
–> nuclear
–> hydro-electric power

23
Q

Concentration = ?

A

number of moles / volume

24
Q

number of moles = ?

A

volume x concentration

25
Q

what does sunlight do?

A

-heat up earth
-re-emitted (go back)
-straight back through cloud
-bounces off clouds
–> increases global temperature
–> greenhouse effect

26
Q

why is distilled water used in practicals?

A

contains fewer chemical impurities than tap water

27
Q

effect of carbon dioxide?

A

-higher levels = increased global warming (blanket forms) –> climate change (
-its a greenhouse gas –> greenhouse effect

28
Q

effect of carbon monoxide

A

toxic gas

29
Q

effect of particulates

A

increased risk of respiratory problems + cancer

30
Q

effect of methane

A

-higher levels = increased global warming (blanket forms) –> climate change
-it’s a greenhouse gas –> greenhouse effect

31
Q

effect of oxides of nitrogen

A

respiratory problems
acid rain
-water + nitrogen dioxide –> nitric acid

32
Q

effect of sulfur dioxide

A

acid rain
-water + sulfur dioxide –> sulfuric acid

33
Q

climate change examples

A

extreme weathers
-droughts
-tornados
-forest fires
-ice melts
-water level rises
-floods
–>affects health

34
Q

reduce acid rain by?

A

-reduce emission of sulfur dioxide
–> use low sulfur fuels
–> use flue gas desulfurisation with calcium oxide at coal burning power stations

35
Q

how do greenhouse gases cause global warming?

A

-absorption, reflection, emission of thermal energy
-reduces thermal energy loss to space

36
Q

removal of nitrogen oxides by catalytic converters?

A

2CO + 2NO –> 2CO2 + N2