# Homework Help: Atmospheric Chemistry, where to start?

1. Feb 2, 2010

### farasha

An atmospheric chemist wishes to measure O3 using a portable “ozone sonde” that will be attached to a helium filled balloon. The mylar balloon is non-elastic and has a fixed volume of 2.0 m3 when filled. The mylar balloon has a mass of 500 g when empty. The ozone sonde has a mass of 750 g. Presume the balloon is filled with He at 1 atm and 298K, and is then launched from the surface.
a) What is the balloons “apparent” density (include mass of He, mylar and ozone sonde). Assume the volume of the ozone sonde is negligible compared to the volume of the balloon.
b) What is the density of the surrounding air at this P and T. Will the balloon float?
c) What will be the balloon’s initial acceleration?
d) Derive an expression for the density of air as a function of height (z) presuming that the pressuredecreases according to the barometric law, and the temperature decreases at the adiabatic lapse rate. (For simplicity you may assume a constant scale height throughout). Calculate the density of air at
0.5km, 1.0 km, 1.5 km, 2.0 km.
e) The balloon is winched upwards using a high strength line with a mass of 250 g/km. Derive an expression for the “apparent” density of the balloon as a function of height (z) (including the effects
of the increasing mass of the line as the balloon rises). Calculate the apparent density of the balloon at 0.5km, 1.0 km, 1.5 km, 2.0 km.
f) How high will the balloon rise?
i know its very long question ... iwant you to help me at least with the first part so i can know whats going on.. belive me i dont even know wut formulas i should use for this
the teacher notes are so easy and his assignment are like hell!!
the forlumlas i knw

for concentration density=nx Mx/Av i know how to find air denisty .....
i also number density nx=Cx na

2. Feb 2, 2010

### farasha

Re: PLZ help me ATMOSPHERIC CHEMISTRYplz help i dont knw where to start?? :-(

so if i want to solve for part a)
density = mass/volume
500g+750g/2.0m^3 is that right???

3. Feb 2, 2010

### farasha

Re: PLZ help me ATMOSPHERIC CHEMISTRYplz help i dont knw where to start?? :-(

and so for part b) air denisty =pMwa/RT

so i got 1.18kg/m^3 is that right.. now how do i knw if the baloon will actually flow or not?

4. Feb 2, 2010

### farasha

Re: PLZ help me ATMOSPHERIC CHEMISTRYplz help i dont knw where to start?? :-(

NEVER MIND GOT HELP FOR THISS :-) just ignore this