Environmental Chemistry Part One Flashcards
(43 cards)
Why is nitrogen important?
It is required by plants to make substances necessary to life.
How can Nitrates be added?
- nitrogen fixing plants (clovers, beans, alfalfa)
- fertilizers/ compost/ manure
- lightning
How can Nitrates be taken away?
- bacteria that convert soil into free N2
- water carries away nitrates
- harvesting plants
What are the natural processes?
Chemical cycles- cycling of elements and compounds through the environment (water)
Cellular respiration- food chemicals and oxygen are used to provide the body with energy, carbon dioxide is produced.
What are Human Activities?
Pollution- any change in the environment that produces conditions harmful to living things (smog and forest fires.)
Agricultural Activities- farmers use chemicals to help control the growth of their crops
Examples of Agricultural Activities?
Fertilizers- chemicals added to the soil to increase plant growth (different ratios of nitrogen, phosphorus, and potassium used to produce different things)
Crop Rotation- crops that are nitrogen fixing increases soil nitrates
Pesticides- chemicals used to kill pests (herbicides=weeds; insecticides=insects’ fungicides-fungus)
Problems of Pesticides?
- not selective and kills pests and non-pests
- some remain in the environment and can be passed onto other organisms
- pests can become resistant to them
What are organic foods?
Foods grown in an environment free of pesticides
What are more Human Activities? 2
Solid wastes- garbage that cannot be recycles is put into land fills lined with plastic and clay.
wastewater/sewage- water with dissolved/undissolved materials is carried by pipes to a septic tank and to water treatment plants
How is sewage treated?
septic tanks- Underground containers where bacteria breakdown organic materials before they are moved out into the soil
Sewage treatment plant- treats wastewater and releases (effluent) into rivers and lakes. Often have nitrogen and phosphorus.
Storm Sewers- large areas used to collect street water before released into rivers and lakes. Contains chemical from the street.
What are more Human activities? 3
Fuel Combustion- oxygen is used to burn fossil fuels and energy (H2O and CO2) is released
Industrial Processes- power generation, mineral processing, fertilizer production, etc
What are fossil fuels? Natural gases?
Fossil Fuels- Fuels formed from dead plants and animals. (coal, oil, natural gas)
Natural gas-Composed of various compounds that can be seperated and used.
What is pH?
A measure of the concentration of hydrogen ions in solutions.
Traits of Acids?
- taste sour
- soluble in water
- corrosive
- conduct electricity
- react with metals
- most formulas start with H
Traits of Bases?
- taste bitter
- soluble in water
- feel slippery
- corrosive
- conduct electricity
- react with acids
- found in soaps, detergents
- end in OH
What are acids? Bases?
Acid- a compound that dissolves in water to form a solution with a pH lower than 7
Base- a compound that dissolves in water to form a solution with a pH higher than 7
What is Neutral ?
A pH of 7.
What is a universal indicator?
shows a wide variety of colors, each indicating a different pH when compared to a color chart
What is neutralization?
A reaction where an acid and base come together to produce water and a salt.
What is a neutralization reaction?
A reaction between an acid and a base where water (HOH) and salt are formed.
What are buffers ?
A substance that can neutralize either an acid or a base.
What is CHON?
Carbon
Hydrogen
Oxygen
Nitrogen
What are organic and inorganic materials?
Organic- molecules with carbon
Inorganic- molecules without carbon
What are nutrients?
elements and compounds needed for living, growing, reproducing
