Section 2: Environmental Chemistry

Test is Friday, March 10th

Toxicity

How poisonous a substance is.

Chlorofluorocarbons

chemicals that have been the result of our thinning ozone layer, they move up into the atmosphere & have been breaking down the ozone layer.

PPM (parts per million)

indicator of the concentration of chemicals in the environment.

LD50 (Lethal Dose 50)

amount of a substance that causes 50 % of a group of test subjects to die if they are given a specified dose of the substance all at once.

Acidity

how acidic a water body is.

Pesticides

substances used to kill pests that are unwanted for the growth of certain organisms.

Scrubbers

Devices that remove Sulfur Dioxide & convert it into C02 & Gypsum. (using limestone)

Heavy Metals

mercury, lead, copper, zinc, cadmium and nickel.

Nitrogen Oxide

forms when nitrogen combines with oxygen as a result of fuel combustion.

Sulfur Dioxide

forms when sulfur combines with oxygen in the air.

Biological Indicators

organisms that help determine water quality.

Carbon Dioxide

a greenhouse gas because its releases in large amounts into the atmosphere (human activities)

Carbon Monoxide

a colorless & odorless gas. Its produced by incomplete combustion of chemicals containing carbon (e.g. hydrocarbons) It mainly comes from motor vehicles

Ozone Layer

a natural formation of ozone above Earths surface that protects s against UV rays.

Greenhouse Effect

certain gasses trap heat from the sun & it regulates the earths temperature.

Ground Level Ozone

When ozone combines with gas emissions, it gets closer to the earths surface and becomes harmful for us to breathe in.

Dissolved Oxygen

how much oxygen from the air is dissolved into a water source

Phosphorus & Nitrogen Content

amount of Nitrogen and Phosphorus in a water source (can cause algal blooms)

Heavy Metals

mercury, lead, copper, zinc, cadmium and nickel

Spring acid shock

concentration of acid that can dramatically lower the pH of the water for a short period of time

How to calculate ppm

Divide solute from solvent then take the answer and multiply by 1,000,000

How to calculate LD50

Divide number of deaths from sample size then multiply the answer by 100 to turn into a percent (Remember to round)

Sulfur Dioxide

forms when sulfur combines with oxygen in the air

Nitrogen Oxide

forms when nitrogen combines with oxygen as a result of fuel combustion

Ozone

(O3) makes up a layer in the atmosphere

Ozone Layer

a natural formation of ozone above Earths surface that protects s against UV rays

Enhanced Greenhouse Effect

Greenhouse effect made greater by human activities that add greenhouse gasses to the atmosphere (this can create global warming)

Monitor

keeping track of something for a specific purpose

5 Categories of water quality

* Human drinking
* Recreation
* Livestock drinking
* Irrigation
* Protection of Aquatic Life

Chemical Factors that affect organisms

* Dissolved oxygen               
* Plant nutrients
* Pesticides
* Salts
* Acidity
* Heavy Metals

Levels of dissolved oxygen depends on

* Temperature
* Turbulence (due to wind or rapids)
* The amount of photosynthesis taking place by water plants and algae
* The number of organisms using up the oxygen in the water

Acidic Deposition

when the soil or water does not have the natural bases to neutralize the acidic precipitation

With every breath we inhale:

78% nitrogen

21% oxygen

some traces of argon, carbon dioxide, hydrogen, and neon.

Air quality can be measured by:

* measuring the levels of pollutants in the air
* estimating the amount of emissions from pollution sources

How do Chlorofluorocarbons affect ozone?

by having products move more slowly through the upper atmosphere, and broken down by the UV radiation.  Upon breakdown, chemicals such as chlorine and bromine are produced, which can destroy ozone.

Acute Toxicity

Serious harm after 1 dose

Chronic Toxicity

Effects noticed after substance builds up