Atmospheric Chemistry, where to start?

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Discussion Overview

The discussion revolves around a problem involving atmospheric chemistry, specifically the measurement of ozone using a helium-filled balloon. Participants explore various calculations related to the balloon's density, the surrounding air density, and the balloon's behavior as it ascends through the atmosphere. The scope includes theoretical and mathematical reasoning related to buoyancy and atmospheric pressure changes.

Discussion Character

  • Homework-related
  • Mathematical reasoning

Main Points Raised

  • One participant outlines the problem and requests assistance with calculating the balloon's "apparent" density, considering the mass of the helium, mylar balloon, and ozone sonde.
  • Another participant proposes a formula for density as mass divided by volume, suggesting a calculation for part a) of the problem.
  • A third participant attempts to calculate the density of surrounding air using the ideal gas law and questions how to determine if the balloon will float based on the calculated densities.
  • A later reply indicates that the participant has received help and suggests to ignore their previous request for assistance.

Areas of Agreement / Disagreement

The discussion does not reach a consensus, as participants are at different stages of solving the problem, and one participant indicates they no longer need assistance.

Contextual Notes

Participants express uncertainty about the formulas needed to solve the problem and the implications of their calculations regarding the balloon's ability to float.

Who May Find This Useful

Students studying atmospheric chemistry or related fields, particularly those working on homework problems involving buoyancy and gas laws.

farasha
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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 what's going on.. believe me i don't 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
 
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so if i want to solve for part a)
density = mass/volume
500g+750g/2.0m^3 is that right?
 


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 balloon will actually flow or not?
 


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

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