Topic 8 Acids and bases - 8.5 Acid deposition

Nature of science:

Risks and problems - oxides of metals and non-metals can be characterized by their acid-base properties. Acid deposition is a topic that can be discussed from different perspectives. Chemistry allows us to understand and to reduce the environmental impact of human activities. 4.8

Understandings

Essential idea: Increased industrialization has led to greater production of nitrogen and sulfur oxides leading to acid rain, which is damaging our environment. These problems can be reduced through collaboration with national and intergovernmental organizations

Rain is naturally acidic because of dissolved CO2 and has a pH of 5.6. Acid deposition has a pH below 5.6.

Acid deposition is formed when nitrogen or sulfur oxides dissolve in water to form HNO3, HNO2, H2SO4 and H2SO3.

Sources of the oxides of sulfur and nitrogen and the effects of acid deposition should be covered.

Applications and skills

Balancing the equations that describe the combustion of sulfur and nitrogen to their oxides and the subsequent formation of H2SO3, H2SO4, HNO2 and HNO3.

Distinction between the pre-combustion and post-combustion methods of reducing sulfur oxides emissions.

Deduction of acid deposition equations for acid deposition with reactive metals and carbonates