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

• Lemon juice• Vinegar• Soda• Pineapple

• These are items that all have a pH less than 7

Common Bases• 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.