[captainkittles]

I cannot figure the following problems out and would LOVE some help:

1) The number of collisions, z, that a molecule in the gas phase makes per unit time, when only one species is present, is given by

             z = pi x d^2 (8kT/pi)^(1/2) p/kT

where d is the collision diameter, m is the molecular mass, T the temperature, and p the pressure. For benzene at 1 Torr and 293K, and assuming d = 5 angstroms, calculate z and hence the pressure broadening change in v, in hertz, of observed transitions

2) Calculate in hertz the broadening change in v of transitions in HCN at 25 degrees celsius due to the DOppler effect in regions of the spectrum typical of rotational transitions (10/cm), vibrational transitions (1500/cm) and electronic transitions (60,000/cm).

3) As a function of frequency, the spectral radiation density is given by

             density(v) = [(8 x pi x h x v^3) / c^3] x [1 / (exp(hv/kT) - 1]

Calculate typical values in the microwave (w = 50 GHz) and near-ultraviolet (wavenumber = 30,000/cm)




ANY HELP WOULD BE VERY APPRECIATED!!!!!!