Pub #brownchem: @alpha137
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Comments in blue

alpha137: Hello

***LizK (gloworm4@167-158-43.ipt.aol.com) has joined channel #brownchem

***LizK: Hello

alpha137: hello again

alpha137: I posted our discussion on the Chem web page in a thing with the mIRC logo

alpha137: Also, I added some comments in blue and there are a couple of links

***LizK: Thank you, I was wondering how to save or print it but I didn;t know how to

alpha137: In the file command in mIRC there is a logging command you can activate.

alpha137: Any how do not worry about it right now since I am doing that from here.

***LizK: Yeah, I got your e-mail about that

***LizK: Ok, thank you

alpha137: We left off with my asking if you could think of some global Tragedy of the Commons ideas. Have any?

***LizK: Well, the whole environmental problem is a large rather obvious example. But there are lots of components of that. For ex. The deforestation of the rain forest. It is to each individuals benifit to cut down the rainforest, but it is detrimental to the world and the farmers themselves in the long run

alpha137: Right

alpha137: Are some of these things population driven?

***LizK: I think so

alpha137: That is, with a smaller population there would not be such a large env. impact.

alpha137: The readings by Sagoff and Erlich are to that point.

***LizK: Yes, because fewer people can do less (depending upon their level of technology etc. but generally speaking)

***LizK: I read those- they were interesting, the two different sides of the picture.

alpha137: So, who is right?

***LizK: I would like to agree with Sagoff because he made it seem as though it would all be ok, technology would come through for humankind and the only reason we should bother to save nature is because we have a moral duty to do so, but I think that Erlich had a very good point and I agree more with him, it seemed to me Sagoff made it all too simplistic.

alpha137: I think so too.

alpha137: My thought is that this is where scientific study can help-be necessary.

***LizK: Yes

alpha137: Is a nation's population itself a Trag. of the Commons example?

***LizK: TO a certain extent.

***LizK: Especially if there is overcrowding or famine or something like that

alpha137: Frankly, I think the world has too many people already.

alpha137: We were talking about water. We know it is essentially conserved on earth, but that there are distribution problems. This too is a commons problem-right?

***LizK: I agree, six billion people is such an enourmous ammount, and I don;t think the earth was ever meant to accomodate that many humans

***LizK: Yes, but not necessarily one that can be fixed very easily

alpha137: An example of how this water problem has really unpleasant consequences is in the middle east.

alpha137: The problem between Israel and Syria in the Golan is not because Syria might

alpha137: have a height advantage, but because of the control of water!

***LizK: And it is even a problem in the US between Ca and some of its neighbors.

alpha137: Yes, and we would mention the Colorado river and Mexico!

***LizK: and who can really control water? IT is formless shapeless and can't very well be picked up if dropped, it would be hard to control it (i think)

alpha137: In the Imperial Valley in Calif. water is subsidized by the government-there are water rights. Now that water is pricy and so land owners are wanting to sell their water rights to make a profit. That means no farming and less food.

***LizK: Thats too bad

alpha137: What about the earth's atmosphere itself. Is that a Trag. of Commons problem?

***LizK: Yes, people can put various chemicals into it and there are not very well defined international limits on how much people can polute the atmosphere,

***LizK: And, another problem deals with the idea of who owns the atmosphere-for planes etc

***LizK: SOrt of like the idea of neutral waters a mile from the coast

alpha137: The control issues require government within national boundaries and between nations for international problems.

***LizK: Yes, but with the pollution issue, it can't be up to one or two countries, it has to be dealt with by all of them, or at least most of them, who will all agree to cooperate

alpha137: If governments are rational (self serving of course) then it would seem that science would be the necessary component for indicating directions of env quality.

***LizK: Yes, so the scientiests would get together and decide?

alpha137: Well, the scientists could get together and study and propose. People decide.

***LizK: Exactly, but it wouldn't do all that much good if three countries decided to follow the standards and the others didn't

alpha137: Have you had the time to read the articles about the "real china problem?"

***LizK: I don't think I've read that one, but I remember reading one which dealt with the prisoner's decion to cooperate or deflect and what the two prisoners would do, and the notion of tit-for-tat cooperation, that seems to relate to this.

alpha137: These articles show how difficult, politically, these issues are.

alpha137: Our task is to understand, scientifically, what is going on.

***LizK: Yes, and they make the prospects for a solution seem bleak given the political atmosphere of our times

alpha137: Part of the motivation is human health and if national leaders are rational then there may be hope.

alpha137: There is more than human health that is of interest however.

***LizK: That is true, no one wants to rule a nation of sick people

***LizK: or watns to be at fault for thier sickness

alpha137: One of the current arguements that Clinton made in China was just that.

alpha137: If environmental controls are lacking then there will be vast medical bills to pay later.

***LizK: And other consequences too

alpha137: The China problem article argues that the gross domestic product for china is decreased by these environmental costs so that actually there is no growth over the long haul.

***LizK: I see, I'll read that today.

alpha137: The point of all this is that we have to understand what is going on in our environment.

***LizK: Yes, that is really important

alpha137: So, since the text starts with air and since we spoke of the atmosphere let us start with that.

***LizK: Alright, I'm ready- I read the first chapter in the text and briefly looked at the secondont

***LizK: "second one" is what I meant

alpha137: OK. I would have rather started with the second and then the first.

***LizK: I'm sorry

alpha137: But the first has the advantage of immediate impact on human health!

alpha137: We started out by asking "what are the conditions for life (human life)?"

***LizK: Yes, I couldn't believe how many particals someone would breathe in every breath of carbon monoxide
I am not sure why carbon monoxide is used here. Should be every breath of air. Carbon monoxide is, of course, an air pollutant. It is also a necessary product of human biology as well.

alpha137: Simply, for life as we know it, we need relatively pure water and relatively pure air! And it cannot be too hot or too cold either.

***LizK: Human life requires 02 to breath and CO2 for the plants and plants themselves, and water and other animalsfor food
It is also true that human life requires a small amout of CO2 to stimulate breathing.

alpha137: Right!!

***LizK: But that is alot in the scheme of things!

alpha137: Here is a problem: Napolean dies and has a last breath. You breathe. Have you breathed in any of the air molecules from Nap's last breath?

***LizK: According to the text yes if the breath were spread out evenly throughout the atmosphere, but it isn't as likely seeing as I'm breating here in Va and he died accross the Atlantic, but since their are so many variables such as weather, it is conseivable

***LizK: And it wansn't spread out evenly accross the atmosphere

alpha137: Right. Molecules are very small. Evenly mixed is necessary. Also we need to know the relationship between numbers of molecules, vol, pressure and temp.

alpha137: Do you remember the ideal gas law?

***LizK: All those gas laws!

alpha137: No, there is only one!

***LizK: yes, PV=nRT

alpha137: Right. Teachers make many gas laws only to confuse you.

***LizK: but what about BOyles and Charles and Gaylussac?

alpha137: They are all derived from PV = nRT

alpha137: Boyle and company did not know PV = nRT and did the best they could.

***LizK: Ok, so there is only one

alpha137: Now, human health is affected by breathing in pollutants like SO2, and

alpha137: ozone.

alpha137: But if there is just the tinyest amount of sulfur dioxide, for example, then there may not be much of a health effect. Right?

***LizK: Yes

alpha137: So, what is important?

***LizK: The concentration

alpha137: Correct.

alpha137: How can we get a concentration from the gas law?

***LizK: That would be 'n' right?

alpha137: That would be n/V.

***LizK: oh, like molaritly, molality normality formality etc, except its molarity (I think)

alpha137: Right

alpha137: If n is moles and V is liters then n/V is moles per liter.

***LizK: Yes,

***LizK: and that is important because then you can measure how much people are exposed to in their daily life

alpha137: Right, right!

alpha137: So, if we know how large a lung is and how many breathes a person takes per day and we know the concentration of stuff in the air then we know how much stuff is breathed in!

***LizK: So the scientests measure the concentration and then figure out how toxic it is so that they can set limits, or have and idea where to set limits

alpha137: Exactly.

alpha137: What is a mole? It is not a small animal.

***LizK: It is a unit of measurement, 6.02*10^23 particles of something

alpha137: It is Avagadro's number (the one you gave) of molecules. It is the number of moleules in a gram molecular weight.

alpha137: If we have 12 grams of carbon then we have 6.023 x 10^23 atoms of carbon.

***LizK: Yes, thats what i meant, but you could have Avagadro's number of atoms and that would be a mole of atoms right?

alpha137: Right

***LizK: Ok, thats basic chemistry, I get that

alpha137: Knowing n (in the gas law) we therefore know the number of grams of a molecule.

***LizK: if you know the atomic mass. but yes, so you can figure out the %comp. by mass

alpha137: And knowing the volume (in liters or sometimes in cubic meters) we know the concentration in grams per volume measure

***LizK: of the substance in the air

alpha137: Right.

alpha137: In the text there is another concentration unit used. It is parts per million.

***LizK: Yes, but that isn't terribly complicated, it is self explanitory

alpha137: We need to be able to define this better and be able to use the gas law to convert to weight per liter.

alpha137: Do they mean ppm by weight or ppm by unit volume?

alpha137: Are these the same?

***LizK: I thought it was by number

***LizK: of particles

alpha137: It is like a percentage, but we need to know if by weight or by volume.
If you use numbers of molecules and we are talking about gas molecules then it seems volume would be a natural. We still have to specify. If we know the number of molecules then we know the weight because we know the molecule weight and therefore the weight of each molecule.

***LizK: Thats what I was thinking

alpha137: The gas law, and Avagadro, will give us numbers of molecules.

***LizK: I think maybe by weight,

***LizK: no, by volue

***LizK: volume

***LizK: because you don't know the relative weights of the particals

alpha137: Well, it can be either, but it must be stated and often is not.

alpha137: In the text it gives a "permissible limit" of ozone of 0.12 ppm. A better unit might be micrograms ozone per cubic meter of air. How can we convert?
Note that 0.12 ppm ozone = 257 micrograms per cubic meter of ozone. How do we get
this conversion?

***LizK: well, .12ppm would be .12 out of a million, so then you could figure out %comp- because you know what the rest of air is made up of?

***LizK: ie, 78%N2 and 21%O2 etc

alpha137: To my simple mind if I know how many breaths per hour and the volume of my lung then I can figure out how many micrograms of ozone and so on.

***LizK: thats easier!

alpha137: Ok. But we are going to have to use the ideal gas law!

alpha137: What are the variables we have to deal with?

***LizK: But only to convert stuff, like from ppm to micrograms and L to m^3

***LizK: Variables are the pressure, temp, volume( but that is the vol of your lungs) R- but that is a constant and n- which you will determine

alpha137: I am thinking that we have to agree on a temperature and a total pressure.

***LizK: Yes, how about 1 atm since we are at sea level, and

alpha137: I guess the pressure would be 1 atm as you suggest and we might as well pick 273K which is the freezing pt of water.

***LizK: ok, thats fine

***LizK: What is the vol. of your lungs?- a liter

***LizK: A liter and a half>

alpha137: Here is the deal. Public health figures do studies on people to determine what concentrations of ozone (to pick an example) that are harmful. They then throw in a safety factor and set a standard that is not to be exceeded in some time.
Click here for a list of the primary standards.

alpha137: I cannot remember the vol of lungs at the moment, but a liter an one half sounds ball part.

alpha137: park

***LizK: Ok so then it is simple math-n=1*1.5/9.O821*273)

alpha137: To determine if the air we breathe is tollerable we have to measure the concentration of pollutants.

alpha137: Yes, it is simple math.

alpha137: I think it is time to stop. We should continue this discussion of the relationship between ppm and regular concentration units next time.

***LizK: ok, thats fine

***LizK: I can't meet tommorrrow morning- when would a better time be?

alpha137: We can also discuss how some measurements are made. Ozone for example is determined by the absorption of ultraviolet light.

alpha137: Let meet next monday?

alpha137: Or Tues?

***LizK: Ok, that sounds good, at this time?

alpha137: OK, Monday at 9:30 am

alpha137: On EFnet again

***LizK: Alright, see you then, have a happy 4th of July!

***LizK: Thank you

alpha137: Thanks, and you too.