Environmental chemistry Flashcards
how are nitrates added to soil
- nitrogen fixing plants
2.fertilizers/compost/manure- lightning
how are nitrates taken away from soil
- bacteria that convert soil nitrates into free N2
- water carries away nitrates
- harvesting plants
what are natural processes and activities that affect environmental chemicals
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
what human activities affect environmental chemicals
- Pollution
- Agricultural Activities
- Solid Wastes
- waste water or sewage
- Fuel combustion
- Industrial Processes
what kinds of pollution are there?
Noise
thermal
chemical
light
what are the types of agriculture activities, what do they do?
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
define industrial process
- Industrial Processes – including electrical power generation, mineral processing and fertilizer production
what is pollution
- Pollution – any change in the environment that produces conditions harmful to living things, such as smog and forest fires
what are agricultural activities?
- Agricultural Activities – farmers use chemicals to help control the growth of their crops.
what are solid wastes
- 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.
define waste water and sewage
- 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.
what are storm sewers
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.
what is fuel combustion
Fuel combustion – oxygen is used to burn fossil fuels and energy, H2O (l), CO2 (g), are released.
What is PH
PH is the measurement of concentration of hydrogen ions
what are properties of acids
taste sour
soluble in water
corrosive
conduct electricity
react with metals
most formulas begin with H (hydrogen)
Examples: HCl - hydrochloric acid
define acid
Acid – a compound that dissolves in water to form a solution with a pH lower than 7
what are properties of bases
Taste bitter
soluble in water
feel slippery
corrosive
conduct electricity
react with acids
found in soaps, detergents
end in OH (Hydroxide )
define base
Base – a compound that dissolves in water to form a solution with a pH higher than 7
define buffer
A buffer is a substance that can neutralize either an acid or a base
define nutrients macro nutrients and micro nutrients
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
What are the 9 macro nutrients
C (carbon)
H (hydrogen)
O (oxygen)
N (nitrogen)
P (phosphorus)
K (potassium)
Mg (magnesium)
Ca ( calcium)
S (sulfur)
what are the Types of Organic Molecules, what are they made of
- Carbohydrates made up of C, H and O
- Lipids
made up of many C, H and O atoms. - Proteins – C, H, O, N
- Nucleic Acids – C, H, O, N, P