Normal Rain (pH 5.6). CO 2 (g) + H 2 O (l) H 2 CO 3 (aq). carbonic acid (a weak acid). Acid Rain (pH < 5.6). NO 2 (g) + H 2 O (l) HNO 3 (aq). nitric acid (a strong acid). Transportation 60%. 2 SO 2 (g) + O 2 (g) 2 SO 3 (g). SO 3 (g) + H 2 O (l) H 2 SO 4 (aq).
Normal Rain (pH 5.6)
CO2 (g) + H2O (l) H2CO3(aq)
(a weak acid)
Acid Rain (pH < 5.6)
NO2(g) + H2O (l) HNO3(aq)
(a strong acid)
2 SO2(g) + O2(g) 2 SO3(g)
SO3(g) + H2O (l) H2SO4(aq)
(a strong acid)
Effects of Acid Rain
1.Damage to Structures Made of Limestone, CaCO3
2. Damage to Plants
Acid rain damages the
surfaces of leafs. This
leaves the plant unable
to make food & more
susceptible to pests &
Acid rain also causesleaching(removal) of minerals from the soil.
Aluminum can block
the uptake of the few
remaining minerals in
Acid rain can kill
3.Damage to Fish Populations
Fish (especially their eggs &
fry) are very sensitive to changes
in pH. Acid rain can cause
pH shockas 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 sectorsnot only for
food, paper, & building materials,
but also for jobs & recreation.
Nitrogen & sulfur oxides
can react with the moisture
in 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 industrial
heartland to these areas.
How Can Acid Rain Be Prevented or Remedied?
Catalytic convertersdecompose nitrogen
& sulfur oxides.
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 has
a low sulfur content.
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
Canadian PM Brian Mulrooney & U.S. President George Bush
signed the Acid Rain Accord in 1991, committing both of their
countries to reduce acid rain emissions.