1. Assume that you are on a planet whose atmosphere does not contain carbon dioxide, only nitrogen, oxygen, and water vapor.
(a) What would be the pH of the rain at 298K?
(b) Lets assume the alien life on the planet lives by eating sulfur and producing sulfur dioxide. If the atmospheric reaches a concentration of 20.0 ppmv of SO2 what would the pH of the rain be at 298K and 1 atm. Use KH for SO2 = 1.12 M/atm and Ka = 1.7x10-2 molL-1
2. (a) Calculate the volume (at 20°C and 1.00 atm) of SO2 produced by conventional roasting of 9.561 tonnes (9561 kg) of copper sulfide ore, CuS.
(b) What volume (in liters) of pure sulfuric acid (d= 1.8305 g/cm3) could be produced from this amount of SO2 if it were oxidized to SO3 and then reacted with water?
(c) The Apblett research group has developed a patent-pending method for converting sulfur dioxide to sulfur and sulfuric acid:
24 SO2 + 16 H2O → S8 + 16 H2SO4
How much sulfur and how much sulfuric acid (in Kg) can be produced from the SO2 according to part (a) of this question.
(d) Look up the prices at Aldrich (either online or a recent chemical catalog) for sulfur and sulfuric acid (use prices for reagent grade material). Which process is more economical? Please show the pricing and your calculations in the answer.
3. (A) If all of the ice on the planet were to melt it would produce 2.8 x 107 km3 of water. The surface area of the ocean is 3.61 x 108 km2. Assuming that all of the water piled up on the top of the ocean and did not spread out, how large would the increase in sea height be (in meters)?
(B) Besides the assumption that the water does not spread out, what other factors may make this calculation incorrect. Hint: Consider the polar ice caps and icebergs and elementary school physics.
4. The rate constant (k) for the reaction XH + OH• → X• + H2O
Is 4.28 x 10-5 molecules-1cm3s-1. If the atmospheric concentration of concentration of OH• radical is 8.04 x 1012 molecules cm-3.
Calculate the half-life of XH.
5. If the concentration of atmospheric CO2 were to double from its current level of 370 ppm, what would be the calculated pH of rainwater (assuming that CO2 were the only acidic input)? With respect to rising CO2 levels, do we have to be concerned about enhanced acidity of rain? See notes below for help with this calculation.
6. If the particle mass concentration on Hall of Fame in front of the construction area is 250 ug/m3, and the average particle size is 0.21 µm, what is the average number of particles/cc?? Assume a density of 0.98 g/ cm3 for the particles.
7. The rate constant for oxidation of nitric oxide by ozone is 2.4 x10-14 cm3/molecule•s whereas that for the competing reaction where it is oxidized by oxygen is 2.3 x10-38 cm3/molecule•s
2 NO + O2 →2 NO2
In a typical morning smog condition the concentration of ozone is 42 ppb and that of NO is 78 ppb. Deduce the rates of the two oxidation reactions. Which one is the dominant process?
8. Assuming the enthalpy and entropy of formation of NO are temperature independent, what temperature (in Celsius) would be required to generate 88 ppmv of NO from the reaction of nitrogen and oxygen? Hint: Use thermodynamic data to calculate ?G with a correction for non-standard conditions for N2, O2, and. NO. The reaction will become thermodynamically possible when ?G=0. Assume atmospheric pressure of exactly 1 atmosphere and normal atmospheric concentrations of nitrogen and oxygen.