Chap 9 - environmental chem Flashcards

1
Q

process of treatment of water

A

-screen the big items
-add coagulant; make soluble things insoluble (ppt & form sediment)
-filter sediment with sand
-add carbon; remove taste & smell
-add chlorine; kill pathogen & microbes
-add fluorine; prevents teeth enamel from decaying
-store water in reservoir

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

water tests (reversible reaction)

A

1) anhydrous Copper (II) sulfate + water ⇌ hydrated Copper (II) sulfate
white ⇌ blue
A CS major W suck- A Comp Sci major Will suck.
2) anhydrous Cobalt (II) chloride + water ⇌ hydrated Cobalt (II) chloride
blue ⇌ pink

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

define groudnwater

A

water from underground

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

define aquifer

A

water from underground

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

define microbe

A

tiny organisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

purpose of coagulant in water treatment

A

reacts with water to produce sediment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

purpose of chlorine in water treatment

A

kill pathogens & microbes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

why may some water be harmful even after treatment

A

-mosquito lays eggs
-algae grows

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

why may fluoride be added in water treatment

A

prevents teeth enamel from decaying

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

how to make dirty water safe for drinking

A

-boil it
-filter it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

how to check if water is impure

A

-melt below 0C
-boils above 100C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

how to get pure water from seawater

A

simple distillation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

air percentages

A

78% - nitrogen
21% - oxygen
1% - other gases (argon, carbon dioxide, water vapor, noble gases)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is decolorizing charcoal made of

A

carbon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

things needed for combustion

A

-fuel
-heat
-oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

colour of metals

A

-all metals are silver except copper & gold
(brown & gold)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

uses of nitrogen

A

-liquid N2 freezes food for transport - low reactivity & abundant supply
-fertiliser

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

uses of oxygen

A

-aerobic respiration
-welding in gas tanks
-fuel cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

uses of noble gases

A

-coloured lights (argon, neon, helium)
-fire extinguisher (argon)
-advertising signs
-balloons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

why do people carry oxygen tanks when mountain climbing

A

-lower oxygen content

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

most reactive gas in air

A

-oxygen
-nitrogen & noble gases aren’t that reactive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

how to separate gases in air

A

-pump air
-remove carbon dioxide & water vapor
-expand & compress gas to liquify it at -200C
-boil liquid & elements gases rises in order of lowest boiling point (fractional distillation)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

order of gases rising in air separation

A

nitrogen, argon, oxygen, krypton, xenon

24
Q

biggest expense when separating air

A

electricity to run for compression & expansion

25
Q

experiment to measure % of oxygen in air

A

-100cm^3 of air in gas syringe
-copper in between gas syringe and another glass
-heat copper as syringe pumps air back & forth
-oxygen is used up to make Copper oxide which changes from brown to black = reaction is complete
-79% air left

26
Q

colour of copper to copper oxide

A

brown to black

27
Q

how to reverse reaction in experiment to measure % of oxygen in air using

A

-fill syringe with helium
-copper is displaced from Copper oxide

28
Q

common pollutant in the air

A

-carbon particles
-sulfur dioxide
-nitrogen monoxide
-nitrogen dioxide
-carbon monoxide
-carbon dioxide
(methane)

29
Q

harmful effects of sulfur dioxide

A

-causes acid rain (react with water vapor in cloud & form sulfuric acid) = acidic soil, kills animals, corrode buildings

30
Q

harmful effects of nitrogen oxides

A

-causes acid rain (react with water vapor in cloud & form nitric acid) = acidic soil, kills animals
-respiratory problems
-nitrogen dioxide = photochemical smog = global dimming (no photosynthesis, warmth, vitamin D)

31
Q

harmful effects of carbon dioxide

A

-increases global warming = climate change = extreme weather conditions, less thermal energy loss to space

32
Q

harmful effects of carbon monoxide

A

-toxic gas to humans (binds to hemoglobin)

33
Q

harmful effects of methane

A

-increases global warming = climate change = extreme weather conditions, less thermal energy loss to space

34
Q

harmful effects of carbon particles

A

-respiratory problems
-cancer risk

35
Q

how is sulfur dioxide formed

A

-combustion of fossil fuels which contain sulfur compounds
-volcanos

36
Q

how is nitrogen oxides formed

A

-made in air from complete & incomplete combustion of nitrogen from high temp & pressure in car combustion engines

37
Q

how is carbon oxides formed

A

-complete & incomplete combustion of fossil fuels containing carbon compounds
(only carbon dioxide)
-respiration
-complete combustion of hydrocarbons

38
Q

how is methane formed

A

-decomposition of vegetation
-waste gas from digestion of animals

39
Q

example of greenhouse gases

A

-carbon dioxide
-methane

40
Q

why is methane not used as a fuel

A

it is a worse greenhouse gas than carbon dioxide

41
Q

ways to reduce climate change

A

-planting trees
-reduction in livestock farming
-decreasing use of fossil fuels
-increasing use of hydrogen and renewable energy, e.g. wind, solar

42
Q

how to reduce sulfur dioxide

A

-use flue desulfurization - react sulfur dioxide with calcium carbonate to make calcium sulfite and carbon dioxide
CaCO3 + SO2 -> CaSO3 + CO2

43
Q

how to reduce nitrogen oxides, carbon monoxide & hydrocarbon

A

-use a catalytic converter - uses a platinum as a catalyst to speed reaction (provide path with lower activation energy)
CO + O2 -> CO2
hydrocarbon + O2 -> CO2 + water
2NO + 2CO → 2CO2 + N2

44
Q

which gases are released in
1) combustion of fuels
2) petrol combustion in cars
3) combustion in air from cars

A

1) CO, CO2, SO2
2) CO, SO2
3)NO, NO2, hydrocarbons

45
Q

reaction between all hydrocarbon & oxygen

A

hydrocarbon + oxygen -> carbon dioxide + water

46
Q

ways to reduce pollutants

A

-use low sulfur fuels
-use flue gas desulfurization
-use catalytic converter

47
Q

define rusting

A

oxidation of iron (iron oxide)

48
Q

things needed for rusting

A

-water
-oxygen

49
Q

note: boiled water doesn’t’ contain oxygen

A
50
Q

ways to prevent rusting

A

-Coating with paint, grease, zinc (galvanizing)
-attach a more reactive metal to iron (sacrificial protection)

51
Q

define galvanising

A

coating something with zinc (electropainting) = barrier method

52
Q

compound in unpolluted air

A

water vapor

53
Q

elements in unpolluted air

A

-nitrogen
-oxygen
-argon

54
Q

uses for water
1) industry
2) house

A

1) cleaning, making clothes
2) drinking, showering

55
Q

note: there is more argon than any other gases in the 1%

A
56
Q

note:
-sulfur dioxide can be used to manufacture sulfuric acid
-carbon dioxide is made in fermentation
-carbon dioxide & metal oxide is made in thermal decomposition of metal carbonates
-combustion of hydrocarbons result in carbon dioxide & water
-household water contains salts

A