ATMOSPHERIC CHEMISTRY
AOSC/CHEM 637
Homework #1
Due: September 13, 2007
1. (2) Write the equation for burning coal in air, assuming that coal is 80% carbon by weight and a stoichiometric air/fuel mixture; assume the rest is noncombustible rock. Write a new equation if coal is 3% S by weight. What will be the concentration of SO2 in the power plant plume (1.0 atm and 150oC) in ppm and ug/m3? When the plume has cooled to 20o C what will be the concentration (again in ppm and ug/m3) if no dilution has occurred?
2. (3) Given the concentrations and Henry's Law coefficients in the following table, calculate the pH, equilibrium vapor pressure in atm, and the mixing ratio in ppb (at 1.0 atm total pressure) appropriate for the following solutions or the air in the head space above the solutions. Assume 298K.
|
Solution |
H (M/atm) |
pH |
Patm |
ppb |
|
0.2 M CH3COOH |
10 |
|
|
|
|
0.1 M HNO3 |
2.1x105 |
|
|
|
|
0.2 M NH4OH |
60 |
|
|
|
|
0.01 M HCl |
106 |
|
|
|
|
10-6 M H2SO4 |
107 |
|
|
|
3. (2) Estimate the temperature and pressure in Shenandoah National Park at the Big Meadows campground, elevation 1100 m, today; note date for which you determined the sea level temperature and pressure. Estimate these values with the integrated form of the hydrostatic (hypsometric) equation and mean lapse rate derived in class.
4. (4) Derive an exact expression for altitude as a function of pressure and temperature assuming a constant surface temperature, T0, and a constant lapse rate, g , of 6.5 K/km. Find the numerical value of the altitude corresponding to the surface temperature and pressure you estimated in Problem 3 above. (the text by Wallace and Hobbs may be helpful.)