Problem Set 3 consists of 2 problems:
A) Problem 13.1 in textbook
1. The United States presently emit to the atmosphere 1.3x109 moles day-1 of NOx and 1.0x109 moles day-1 of SO2. We assume that all of the emitted NOx and SO2 are precipitated back over the United States as HNO3 and H2SO4, respectively (this is not a bad approximation). The area of the United States is 1.0x107 km2 and the mean precipitation rate is 2 mm day-1. Assuming that HNO3 and H2SO4 are the only impurities in the rain, show that the resulting mean pH of precipitation over the United States is 3.8
2. What is the actual range of rainwater pH values over the United States? Explain your overestimate of rainwater acidity in question 1.
B) Dinosaurs and Acid Rain
A dinosaur extinction theory suggests that a falling asteroid 65 million years ago would have led to extremely acid global rainfall, killing the land vegetation and hence the dinosaurs’ food supply. What acid(s) could have been involved?