Question

Consider two lakes, North Lake and South Lake. North Lake has a granite base, and South Lake has a limestone base. Each of them is exposed to acid deposition, primarily from nitric acid. Both lakes have volumes of 3 × 106 m3, surface areas of 1.0 × 105 m2, and are fed by springs that have no nitric acid and have flow rates of 75 m3/day. a. Calculate the pH of North Lake if it experiences a nitric acid deposition rate of 1.5 × 10–10 mol m–2 day–1 . Remember, granite lake beds do not buffer acids. The pH could be very low, due to the lack of any nitric acid removal processes other than its dissociation and dissolution processes. b. Calculate the pH of South Lake if it experiences the same nitric acid deposition rate. This time, there is limestone to buffer the nitric and carbonic acids.

Answer 1