Acid rain formation involves a chain of events that begins with emissions from…
CHEMISTRY · Multi-part · GCSE · Chemistry · Chemistry of the Atmosphere · Chemistry of the Atmosphere
Problem
Acid rain formation involves a chain of events that begins with emissions from industrial smokestacks and ends with observable environmental consequences. Consider the following simplified sequence:
(a) Classify each step (1–5) as a physical change, a chemical change, or a combination. Justify each classification by citing macroscopic evidence or reaction stoichiometry as appropriate.
(b) For step 2, write a balanced equation for the combustion of elemental sulfur present in coal. Include physical states.
(c) Predict how the concentration of hydrogen ions in rainwater would change if flue-gas desulfurization units removed 90 % of sulfur oxides before step 4. Explain your reasoning qualitatively; no numerical calculation is required.
(d) The environmental scientist claims that the erosion of marble in step 5 involves both physical and chemical changes. Construct an argument that supports or refutes this claim, incorporating evidence from mineral composition, reaction products, and observable morphology changes.
(e) Propose a feasible industrial or environmental intervention (other than flue-gas desulfurization) that would reduce the chemical changes leading to acid rain. Explain how your intervention alters one or more steps in the sequence and classify the type of change it introduces.