# How to keep raccoons away

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• posted on May 27, 2004, 3:11 pm

Well, the way you're using it IS a bunch of hokey. You've calculated molar density, not mass density. That's equivalent to saying 100 bowling balls takes up more space than 100 baseballs, since a 'mole' is just a fixed number of atoms (somewhat more than a 'sh*tload'). It says nothing about which is 'heavier'. You're better off just ignoring molar density (as the previous poster did ) since, as you note, they're all pretty close, and just going with the mass density. CO2 is denser than 'air', and CO is slightly lighter.
Kelly

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<%-name%>
• posted on May 27, 2004, 4:36 pm
snipped-for-privacy@ptdcs2.intel.com (Kelly E Jones) wrote in wrote:

http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch4/deviation5.html

100 bowling balls do take up more space than 100 baseballs, and the size of the molecules is something the Van der Waals equation takes into account that the Ideal Gas equation does not. (at STP the variation is not very significant, but if you use the ideal gas equation, obviously you get the same answer for every compound). [for people who don't remember their chemistry a mole is Avogadro's number of particles ~= 6.02 x 10^23]
If you take the molar density and multiply by the molecular weight, you get the mass density.

Assuming the numbers are right, oxygen has more mass density than carbon monoxide (but slightly less particle density). For purposes of asphixation, the CO vs O2 comparison is what matters.
I still can't work out how mass density is relevant when talking about gases or how adding atomic weights can give a correct indication of density or buoyancy. It would be akin to saying water floats on oil (obviously it doesn't), because water (1 + 1 + 16 = 18) is lighter than oil (say minimum of 2 H and 2 C = 26). To me it makes more sense (when talking about gases at least) to talk about particle density, but I'm not convinced particle density is the solution, either.

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<%-name%>
• posted on May 27, 2004, 4:52 pm

True!
Not really... O2 and N2 don't separate out - they form, effectively, a 'solution', so the density of 02 is not really relevant. It's the density of 'air' which matters, which is between the density of air and nitrogen (and closer to nitrogen).

Because mass density, coupled with gravity, is what causes bouyancy.

Because for most gases (at fixed temperature and pressure), the molar volume (molar density) is roughly constant, thus the molecular weight is a good indicator of the mass density, which determines bouyancy.
If we say that a mole of any gas occupies roughly 24 liters at STP, and a mole of gas weighs it's molecular weight in grams, then the density of any gas is proportional to it's molecular weight. The density of CO2 is thus about 44 grams per 24 liters.

No, gases and liquids are vastly different phases. The molar volume of most gases (at STP) is roughly the same; the molar volume of liquids can be orders of magnitude in difference.

Nope, not at all. Gravity doesn't care at all about particles, it only cares about mass...
Kelly

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<%-name%>
• posted on May 27, 2004, 7:01 pm
That makes sense, thanks for the explanation.
snipped-for-privacy@ptdcs2.intel.com (Kelly E Jones) wrote in wrote:

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<%-name%>
• posted on May 28, 2004, 1:08 am
Kelly E Jones wrote:

<snip>
<snip>
This property can come in very handy, as long as you know a few key atomic weights. Say, for instance, that you're stuck in a boring class or lecture. No problem. Whip out your pencil and notepad and calculate how much H2 it would take to float your neighbor's cat into the stratosphere. Next, calculate how much He to do the same thing. Look up at the lecturer from time to time, appearing thoughtful. He or she will be impressed that you're taking more notes than any one else in the room.
The above is a purely hypothetical scenario. <g>
R, Tom Q.

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<%-name%>
• posted on May 28, 2004, 12:45 am
Salty Thumb wrote: <snip>

As I mentioned in my previous post, I think those volume figures are a little off.
According to my handy-dandy Pocket Ref, here are the densities (@ STP):
O2    1.4290 g/L N2    1.2506 g/L CO    1.2500 g/L CO2    1.9770 g/L Air    1.2928 g/L
Just as a sanity check, I multiplied each one of those figures by 22.4 to make sure that the product was close to the molecular mass (they are).
R, Tom Q.

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<%-name%>
• posted on May 28, 2004, 1:13 am

Erg. Now you've made me realize that mis-remembered that the molar volume of a gas is 22.4, not 24 as I stated in my previous posts. Been a long time since college...
Kelly

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<%-name%>
• posted on May 28, 2004, 2:29 am
snipped-for-privacy@ptdcs2.intel.com (Kelly E Jones) wrote in wrote:

The volume is around 24.04 L/mol at 20C, 1 atm (which is the temp I calculated at) and 22.4 L/mol at STP.

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• posted on May 28, 2004, 2:19 am

Ha, thanks, but mine were way off. This is why I am not a chemist (or mathematician). The correct equation is probably: v^3 - (b + RT) v^2 + a V - ab = 0 (forgot to multiply RT by v^2 last time)
which gives CO 1.168 g/L at 20C, 1 atm CO 1.253 g/L at STP (using 28 for mass)
Close enough to the value you reported.
Calculations for other compounds are an exercise left to the reader

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<%-name%>
• posted on May 28, 2004, 12:21 am
Salty Thumb wrote: <snip>

I think there's something wrong with those numbers. 1 mole of (ideal) gas occupies 22.4 L @ STP. Your numbers should vary slightly.
Kelly's already done a bang-up job of explaining why you need to bring mass back into the picture.
R, Tom Q.

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<%-name%>
• posted on May 28, 2004, 12:51 am

Um. Hate to be practical and everything here, but if you're forcing a gas into the gopher hole, the density doesn't matter; it's not going there by gravity, it's going there by pressure. You could force helium down there and it'd go down rather than up, density and molecular mass notwithstanding.

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<%-name%>
• posted on May 27, 2004, 3:29 pm

ache.
Brownian motion will cause gases to mix. You don't see the O2 and N2 that compose most of our "air" separating.

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<%-name%>
• posted on May 27, 2004, 4:36 pm

But isn't it true that there exists some "heavy" gas that will tend to collect at a lowest elevation? I don't remember exactly what carbon monoxide does, but it's possible that I've also heard that it sinks (compared to say something like helium which obviously wants to rise).
The question is whether CO is one of those gases.

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<%-name%>
• posted on May 28, 2004, 11:39 am
On Thu, 27 May 2004 16:36:23 GMT, Salty Thumb

Is not...Oxygen (O2, molecular wt 32) will settle slowly...Carbon Dioxide (CO2, molecular wt 44) settles fairly well...Propane (C3H8, also molecular wt 44), settles well enough to cause major problems if a leak occurs.
ck
--
country doc in louisiana
(no fancy sayings right now)

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<%-name%>
• posted on May 28, 2004, 2:42 am

actually, carbon monoxide, at mol wt 28 (same as N2) is slightly lighter than air (avg formula wt approx 30).
and there have been a number of documented human survivors from failed CO suicide attempts because the engines shut down before the air in the garage became lethal.
and cigarette smokers frequently tolerate levels of carboxy hemoglobin that would debilitate folks who didn't smoke.
ck
--
country doc in louisiana
(no fancy sayings right now)

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<%-name%>
• posted on May 10, 2004, 5:06 pm

emergency
gunshots.
and
Animal Control here WILL NOT deal with anything but dogs and cats and the occasional potbelly pig. Raccoons are *wildlife* and therefore non-domestic and not their problem. If you have an injured one, the state wildlife guys will direct you to a vet and foster parent, but they don't deal with them either unless they're possibly rabid, and since that's not happened since sometime in the 70's, you just get told to call a pest control firm who'll charge you big bucks and still not solve your problem.
If the original poster and his child are too stupid to install an electric wire like was recommended, then let him deal with no fish in the fish ponds and no veggies in the garden and several ER bites from trying to trap them. Evolution in action. He'll either learn what futility is, or he'll actually educate himself on electric fences and not subscribe to ignorant hysteria. I'll bet he's even touched his tongue to a battery as a child, but somehow he thinks that should have electrocuted him.

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<%-name%>
• posted on May 10, 2004, 5:27 pm

enlist
non-domestic
Hmm. They were more than happy to come over to my house to remove a raccoon that was wandering around the yard in broad daylight. Is it possible that animal control departments are different from one place to another? Would it hurt to call and ask?

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<%-name%>
• posted on May 10, 2004, 5:49 pm

enlist
non-domestic
ponds
them.
actually
I'm pretty sure it takes more than 9v to scare off a racoon. So how much voltage would you use that would do the job but not hurt the child? I know you can die from as little as 50v. Even less if you got imaginative.

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<%-name%>
• posted on May 10, 2004, 8:26 pm

hysteria.
somehow
know
Don't let your kids wear wool socks on a low humidity day...imagine what would happen if they discovered they can shuffle around the house and zap each other with a few thousand volts. A typical static electricity shock is about 2000 - 4000 volts.
Of course a amperage involved is so low, that aside from the surprise, no damage is done. Ever taken a weak 9v battery and tapped it against your tongue? A fresh battery hurts a little, but a weak one gives a little tingling sensation.
A consumer grade electric fence is harmless, it will give a mild shock, but nothing dangerous. I couldn't find the specifications online, so guestimating, if an electric fence transformer draws 120v A/C @ 1 amp, the output would be 4000 v A/C at .03 amp.
That's just a mild shocker, pretty safe..if it was D/C on the otherhand is a different story.
Sameer

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<%-name%>
• posted on May 10, 2004, 9:23 pm
snipped-for-privacy@sbcglobal.net says...
<snip> <A consumer grade electric fence is harmless, it will give a mild shock, but <nothing dangerous. I couldn't find the specifications online, so <guestimating, if an electric fence transformer draws 120v A/C @ 1 amp, the <output would be 4000 v A/C at .03 amp. < <That's just a mild shocker, pretty safe..if it was D/C on the otherhand is a <different story. < < <Sameer < <
Doesn't matter whether it's A/C or D/C.
Here's a reference:
<http://www.osha.gov/SLTC/etools/construction/electrical_incidents/eleccurrent.html
Bill