Transcript ACID RAIN - Duluth High School

ACID RAIN
WHAT IS ACID RAIN??
• Acid rain describes any form of precipitation
with high levels of nitric and sulfuric acids.
• It can also occur in the form of snow, fog,
and tiny bits of dry material that settle to
Earth.
• When humans burn fossil fuels, sulfur dioxide
(SO2) and nitrogen oxides (NOx) are released
into the atmosphere. These chemical gases
react with water, oxygen, and other substances
to form mild solutions of sulfuric and nitric acid.
Winds may spread these acidic solutions across
the atmosphere and over hundreds of miles.
When acid rain reaches Earth, it flows across the
surface in runoff water, enters water systems,
and sinks into the soil.
ACID RAIN DAMAGES…
• LAKES AND STREAMS- makes waters acidic and
causes them to absorb the aluminum that makes
its way from soil into lakes and streams. This
combination makes waters toxic to crayfish,
clams, fish, and other aquatic animals.
• This can lead to fish kills.
• Most fish cannot survive in water with a pH less
than 4.5
• Many lakes in Norway, Sweden, Ontario, Canada
and NE US have few if any fish.
Damage to aquatic life
ACID RAIN DAMAGES…
• TREES- Acid rain also damages forests, especially
those at higher elevations. It robs the soil of
essential nutrients and releases aluminum, lead
and mercury into the soil, which makes it hard
for trees to take up water. Trees' leaves and
needles are also harmed by acids.
• The effects of acid rain, combined with other
environmental stressors, leaves trees and plants
less able to withstand cold temperatures,
insects, and disease.
ACID RAIN DAMAGES…
• CROP YIELDS- if the pH is below 5.1, plant
productivity is reduced.
• Low pH levels affect nutrients by converting
them into forms that are not readily available to
the crop.
• In addition, low pH levels can increase the
solubility of plant toxic metals such as aluminum
resulting in stunted growth and a general lack of
plant vigor.
ACID RAIN ALSO DAMAGES …
• MONUMENTS, STATUES, TOMBSTONES,
METALS AND CAR FINISHES.
• The chemical reactions between the acid rain
and the building materials may dissolve the
chemicals that make the structures.
Cleopatra’s Needle, Central Park
Affected vegetation
Pine needles in the Black Forest,
Germany
The pH scale
• A scale that measures how acidic or basic a
substance is. The pH scale formally measures the
activity of hydrogen ions in a substance or
solution.
• Goes from 0-14
• We are around all sorts of acids in bases in our
daily lives.
Common Acids
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Lemon juice
Vinegar
Soda
Pineapple
• These are items that all have a pH less than 7
Common Bases
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Any cleaning product
Blood
Ammonia
Soap
Laundry detergent
Baking soda
• These are all items with a pH above 7
The pH Scale is based on the number 10 (it’s logarithmic)
• So, a pH of 6 is 10 times more acidic than a pH of 7.
• A pH of 2 is 10 times more acidic than a pH of a 3 and
100 times more acidic than a pH of 4.
• A pH of 8 is 9 times more acidic than a pH of 10, but we
could also say that a pH of 9 is 10 times more basic than
a pH of 8.