Environmental chemistry Flashcards

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1
Q

how are nitrates added to soil

A
  1. nitrogen fixing plants
    2.fertilizers/compost/manure
    1. lightning
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2
Q

how are nitrates taken away from soil

A
  1. bacteria that convert soil nitrates into free N2
    1. water carries away nitrates
    2. harvesting plants
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3
Q

what are natural processes and activities that affect environmental chemicals

A

Chemical Cycles – cycling of elements and compounds through the environment, like the nitrogen cycle
Cellular respiration – food chemicals and oxygen are used to provide the body with energy, carbon dioxide is produced

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4
Q

what human activities affect environmental chemicals

A
  1. Pollution
  2. Agricultural Activities
  3. Solid Wastes
  4. waste water or sewage
  5. Fuel combustion
  6. Industrial Processes
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5
Q

what kinds of pollution are there?

A

Noise
thermal
chemical
light

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6
Q

what are the types of agriculture activities, what do they do?

A

a) Fertilizers - chemicals added to the soil to increase plant growth.
- usually contain nitrogen, phosphorus and potassium, three elements essential for plant growth. Sometimes sulfur is added.
b) Crop rotation
Crops that are nitrogen fixing increase soil nitrates
eg. clover, alfalfa and peas
c) Pesticides - chemicals used to kill pests (organisms that harm people, crops or structures).
- grouped by what they kill: herbicides kill weeds,
insecticides kill insects, fungicides kill fungus

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7
Q

define industrial process

A
  1. Industrial Processes – including electrical power generation, mineral processing and fertilizer production
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8
Q

what is pollution

A
  1. Pollution – any change in the environment that produces conditions harmful to living things, such as smog and forest fires
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9
Q

what are agricultural activities?

A
  1. Agricultural Activities – farmers use chemicals to help control the growth of their crops.
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10
Q

what are solid wastes

A
  1. Solid Wastes – garbage from homes and industry that cannot be recycled is put into landfills which are specially constructed with plastic liners and compacted clay to prevent chemicals leaking into the ground (leaching).
    Some solid waste is incinerated or burned at high temperatures and some of the gases released contribute to air pollution.
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11
Q

define waste water and sewage

A
  1. Wastewater or Sewage – water containing dissolved and undissolved materials, called sewage, is carried by pipes into a septic tank in rural areas and to water treatment plants in the city.
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12
Q

what are storm sewers

A

Storm sewers – large areas used to collect street water before it is released into rivers and lakes. This water contains chemicals washed off the street.

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13
Q

what is fuel combustion

A

Fuel combustion – oxygen is used to burn fossil fuels and energy, H2O (l), CO2 (g), are released.

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14
Q

What is PH

A

PH is the measurement of concentration of hydrogen ions

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15
Q

what are properties of acids

A

taste sour
soluble in water
corrosive
conduct electricity
react with metals
most formulas begin with H (hydrogen)
Examples: HCl - hydrochloric acid

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16
Q

define acid

A

Acid – a compound that dissolves in water to form a solution with a pH lower than 7

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17
Q

what are properties of bases

A

Taste bitter
soluble in water
feel slippery
corrosive
conduct electricity
react with acids
found in soaps, detergents
end in OH (Hydroxide )

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18
Q

define base

A

Base – a compound that dissolves in water to form a solution with a pH higher than 7

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19
Q

define buffer

A

A buffer is a substance that can neutralize either an acid or a base

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20
Q

define nutrients macro nutrients and micro nutrients

A

Nutrients
elements and compounds needed for living, growing and reproducing

Macronutrients
9 elements that are needed in large amounts.
C, H, O, N, P, K, Mg, Ca, S.

Micronutrients
elements needed only in trace amounts
Eg. Fe, Se

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21
Q

What are the 9 macro nutrients

A

C (carbon)
H (hydrogen)
O (oxygen)
N (nitrogen)
P (phosphorus)
K (potassium)
Mg (magnesium)
Ca ( calcium)
S (sulfur)

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22
Q

what are the Types of Organic Molecules, what are they made of

A
  1. Carbohydrates made up of C, H and O
  2. Lipids
    made up of many C, H and O atoms.
  3. Proteins – C, H, O, N
  4. Nucleic Acids – C, H, O, N, P
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23
Q

what is passive transportation?

A

movement of molecules that doesn’t require any energy

24
Q

what is active transportation?

A

energy is used to move molecules against the current (low concentration to high)

25
Q

define biomagnifacation

A

the concentration of toxins in an organism as a result of its ingesting other plants or animals in which the toxins are more widely disbursed.

26
Q

Whats the ozone layers function?

A

the function of the ozone layer is to shield the Earth from damaging ultraviolet radiation from the sun.

27
Q

What five categories of water are guidelines in place for?

A

Human drinking water
Recreation
Livestock drinking water
Irrigation
Protection of aquatic life

28
Q

what are biological indicators

A

organisms that live in water help determine its quality.

29
Q

what is a microbiological indicator

A

a type of biological indicator where samples are taken from water sources people use to determine the number and type of microscopic organisms, such as bacteria, that are there in order to avoid illness.

30
Q

whats an aquatic biological indicator

A

nvertebrates (animals without backbones) such as insects, crustaceans, worms and mollusks can be used as indicators of water quality since different invertebrates prefer different living conditions, such as dissolved oxygen, pH and temperature.

31
Q

what are the chemical factors that affect organisms

A
  1. Dissolved Oxygen
  2. Phosphorus and Nitrogen Content
  3. Acidity
  4. Pesticides
  5. heavy metals
32
Q

How can toxicity affect organisms, how do we measure it?

A

Measuring Toxicity – different chemicals affect organisms in different ways, so it can be difficult to compare the toxicity of a substance to other substances.
A measurement called LD50 indicates the amount of the substance that will cause 50% of the population to die

33
Q

how do pesticides affect organisms, whats the problem with them

A

Pesticides – some have long term toxic effects because they don’t degrade and become trapped in the tissues of animals. Many today are engineered to decompose after 1 season

there problem is pests become resistant over time

34
Q

how does acidity affect organisms, provide an example

A

Acidity – as the pH of a water system drops the diversity of plants and animals that can live in the water decreases. Below 4.5, most fish disappear. Acid deposition is a problem in areas where soil and water lack bases to neutralize it.

for example Spring acid shock occurs when acid builds up in the snow and then is released into the waterways as the snow melts, causing a dramatic drop in pH that seriously affects water organisms.

35
Q

how does nitrogen and phosphorus content affect organisms

A

Phosphorus and Nitrogen Content – these nutrients are added to water by sewage and runoff from fertilized fields.
Higher concentrations lead to increased growth of algae and green plants and eventually a buildup of dead matter.

This encourages a decomposer bloom, then bacteria increases to decompose the algae, then, dissolved oxygen decreases.

36
Q

how does dissolved oxygen affect organisms

A

Dissolved Oxygen – the amount of oxygen dissolved in a body of water depends upon:
water temperature- more oxygen in cold water Turbulence - more oxygen in turbulent water
amount of photosynthesis
number of organisms living in it - they consume oxygen.

37
Q

how do we measure chemicals

A

Measuring Chemicals – the concentration of chemicals is measured in parts per million (ppm) or milligrams per litre (mg/L).

38
Q

how do heavy metals affects organisms

A
  1. Heavy Metals – metals such as copper, lead, zinc, mercury, cadmium and nickel have densities greater than 5 g/cm3 and are therefore called heavy. They occur naturally in the environment but not usually in large amounts.
    Human activities can increase the amount of these metals
    These metals are toxic to many organisms, but are very harmful for children.
39
Q

what is air made up of, how do we determine its quality?

A

Air is made up of 78% nitrogen, 21% oxygen, less than 1% argon and other trace gases (0.03%).
It’s quality is determined by
1) measuring the pollutants
(more accurate)
2) estimating the amount of emissions from pollution sources.

40
Q

What is Sulfur Dioxide

A

this pollutant comes from industrial processes, like the oil and gas industry in Alberta, and from the burning of fossil fuels (coal, oil and gas).
It contributes to smog and acid rain and can affect your respiratory system.

41
Q

what are scrubbers used for

A

Scrubbers are used to remove up to 99% of sulfur from industrial emission by using limestone (calcium carbonate) to convert it to a useful product called gypsum, and carbon dioxide.

42
Q

what are nitrogen oxides

A

These pollutants are formed mainly by fossil fuel emissions and by combustion at generating plants and industrial processes.

43
Q

what are catalytic converters, what are they made of?

A

Catalytic converters make CO2 out of CO since it is very toxic when inhaled – it leads to headaches, sleepiness, brain damage and death.
Catalytic converters use Platinum and Palladium to remove pollutants from vehicle exhaust.

44
Q

what is carbon monoxide

A

‘the silent killer’, colorless and odorless, it is a deadly gas that is produced by the burning of fossil fuels and can be produced when anything containing carbon is burned (wood like when heating homes or in forest fires, natural gas, cigarettes and industrial processes).

45
Q

what is ground-level ozone

A

a colorless, odorless gas in the upper atmosphere that protects the earth from harmful UV radiation. At the earth’s surface, ozone is formed by reactions between oxygen, nitrogen and volatile organic chemicals (VOCs – emitted from solvents and gasoline).
Ozone at the earth’s surface is a pollutant because it affects the respiratory systems

46
Q

what is a greenhouse gas

A

gases in the atmosphere that trap heat from the sun’s radiation. These greenhouse gases include water, methane, nitrogen oxides and carbon dioxide.Many scientists support the theory that human activities enhance the greenhouse effect which increases the global temperature

47
Q

how is carbon dioxide released

A

CO2 is released naturally into the air by people breathing, driving vehicles and combusting materials.

48
Q

what is the ozone layer

A

The ozone layer is 15 to 50 km above the earth and protects us from UV rays. Scientists have found that this layer has become thinner over the years, some places so thin that they are called holes.

49
Q

what is the direction and distance of materials in air determined by

A

Pollutant properties
Wind Speed
Wind Direction

50
Q

what is the ground water zone

A

All space between soil grains is filled with water.

51
Q

define permeable soil

A

The soil is loosely packed and the pores are connected. Water can easily flow.

52
Q

define leachate

A

Water moving through the soil that contains dissolved substances.

53
Q

define dispersion

A

Dispersion: Scattering of Substance away from its source.

54
Q

define dilution

A

Dilution: Mixes the pollutant with water or air.

55
Q

define biodegradtion

A

Biodegradation: Worms, fungi, and bacteria breakdown substances.

56
Q

what is mercury

A

Mercury is a toxin affecting the brain