Normal Rain (pH 5.6)

CO2 (g) + H2O (l) H2CO3 (aq)

carbonic acid(a weak acid)

Acid Rain (pH < 5.6)

NO2 (g) + H2O (l) HNO3 (aq)

nitric acid(a strong acid)

Transportation60%

2 SO2 (g) + O2 (g) 2 SO3 (g)

SO3 (g) + H2O (l) H2SO4 (aq) sulfuric acid(a strong acid)

Industrial Sources 68%

Electric Utilities27%

Effects of Acid Rain

1. Damage to Structures Made of Limestone, CaCO3

2. Damage to Plants

Acid rain damages the surfaces of leafs. Thisleaves the plant unableto make food & more susceptible to pests & diseases.

Acid rain also causes leaching (removal) of minerals from the soil.

Aluminum can block the uptake of the fewremaining minerals inthe soil.

Acid rain can killthe decomposersin soil.

3. Damage to Fish Populations

Fish (especially their eggs &fry) are very sensitive to changesin pH. Acid rain can cause pH shock as the snow & ice melts in the spring.

Acid rain can cause the aluminum in soil to enter ponds & lakes. Fish respond to the aluminum by producing excess mucous on the surface of their gills. The result is death by suffocation.

4. Harm to Human Beings

We depend upon the forestry, fishing, & agricultural sectors not only for food, paper, & building materials, but also for jobs & recreation.

Nitrogen & sulfur oxidescan react with the moisturein our lungs to produce acids.

As a result of acid rain, toxic minerals (e.g.- Hg) can be leached out of soil and into our drinking water.

Why Are Certain Areas More Sensitive to Acid Rain Than Others?

bedrock consists of granite,which is NOT a base

bedrock consists of a base - limestone or CaCO3

(i.e.- a vast inland sea was once located in this area)

The Great Lakes Lakes in the Canadian Shield

The prevailing winds carry acid rain emissions from their sources in southern Ontario & the American industrialheartland to these areas.

How Can Acid Rain Be Prevented or Remedied?

Catalytic converters decompose nitrogen& sulfur oxides.

Scrubbers

These devices spray a solution containing limestone powder into the smokestack. This causes the sulfur dioxide to become neutralized.

“Soft” (Bituminous) Coal

This is coal that hasa low sulfur content.

Liming

The process of adding a lime or calcium hydroxide (a base)to acidified lakes.

Use Energy Sources that Don’t Produce Nitrogen or Sulfur Oxides

Legislation

Canadian PM Brian Mulrooney & U.S. President George Bushsigned the Acid Rain Accord in 1991, committing both of theircountries to reduce acid rain emissions.

Lifestyle Decisions

conserve electricity

drive less