Why are the populations of young aquatic animals in an ecosystem often a good indicator of the overall health of the ecosystem?

(a) What two groups of compounds are largely responsible for causing acid precipitation? (b) Write a chemical equation(s) to illustrate how one of these compounds reacts to produce acid precipitation.

Rain is naturally acidic. Under what conditions does “normal” rain become “acid” rain?

Consider two neighbouring lakes in an isolated region of Ontario. One lake is on limestone (calcium carbonate) while the other is lined with granite. Both receive the same amount of acid precipitation, (a) Explain why the limestone lake has a higher pH than the granite lake. (b) Which lake is likely to have a healthier aquatic ecosystem? Explain your answer.

(a) Calcium oxide, CaO, reacts with water to form calcium hydroxide. Write the chemical equation for this reaction. (b) Why is calcium oxide capable of neutralizing acids despite not having the hydroxide ion in its chemical formula? (c) Explain why adding calcium oxide (sometimes called “lime”) to lakes polluted with acid precipitation solves the problem only tor the short term. (d) Suggest a permanent solution to the problem.

(a) How do acid rain and acid precipitation differ? (b) Acid precipitation is sometimes called “wet deposition” Why is this term appropriate? (c) How do wet and dry deposition differ?