ATMOSPHERIC CHEMISTRY

AOSC/CHEM 637

Homework #1

Due: February 8, 2011

1. (3) Write the equation for burning coal in air, assuming that coal is pure carbon and assume a stoichiometric mixture. Write a new equation if coal is 17% hydrogen and 3% S by weight. What will be the concentration of CO2 and SO2 in the power plant plume (1.0 atm and 150oC) in ppm and m g/m3? When the plume has cooled to 20o C what will be the concentration (again in ppm and m g/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 1.0 M NH4OH 60 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. (Wallace and Hobbs may be helpful.)