Transcript acid rain
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) Transportation 60% 2 SO2 (g) + O2 (g) 2 SO3 (g) SO3 (g) + H2O (l) H2SO4 (aq) sulfuric acid (a strong acid) Electric Utilities 27% Industrial Sources 68% 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 & diseases. Acid rain also causes leaching (removal) of minerals from the soil. Aluminum can block the uptake of the few remaining minerals in the soil. Acid rain can kill the decomposers in soil. 3. Damage to Fish Populations Fish (especially their eggs & fry) are very sensitive to changes in 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 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 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 has a 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 Bush signed the Acid Rain Accord in 1991, committing both of their countries to reduce acid rain emissions. Lifestyle Decisions drive less conserve electricity