Question on Carbon Monoxide gas

There seems to be differences of opinions on the properties of carbon monoxide gas. One source says its heavier than air another says its
lighter, so.......is it heavier or lighter than air?
To be honest I rather trust the info from this forum than various websites and media types.
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snipped-for-privacy@hotmail.com (Roy) wrote:

And you slept though Chemistry, saying "when will I ever use this boring stuff..."
CO: 12+16(, .vs. air, a mixture of 78% 14+14 (N2) and 21% 16+16 (O2), plus 1% others. So, slightly lighter than air. But not much. And very, very deadly in high concentrations - read a bit on the wood/biomass gasification websites to be reminded - evidently the old "head in the oven" method of suicide dated back to cooking gas that was mostly CO, and 1 or two deep breaths would do the job...
Don't know what you are doing, but I suggest a CO meter/alarm with a digital readout - $50 bucks or so, well spent.
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On Thu, 05 Jan 2006 15:07:57 GMT, Ecnerwal

The worst things about CO are that it sticks to hemoglobin better than oxygen and that it accumulates in your blood. So even with very small amounts present in the air you can be poisoned and die. This is also why just removing someone from exposure to the gas won't guarantee survival. I believe it also affects other organs besides the brain. ERS
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(Roy) wrote:

There's also the matter of diffusion and convection - just because a gas is heavier than air doesn't mean it will all sink to the floor.

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(Roy) wrote:

CO 12+16( (14+14)+ (16+16) ??
By that reasoning Beryllium is lighter than air at a molecular weight of 9.0112. Simply adding molecular weights or even their atomic number is not a method of determining density. Realize that if you take one liter of water and add 100 cc of salt to that water and stir until it is dissolved you will not necessarily end up with 1.1 liters of material.
The specific gravity of CO is 0.968 times that of air. It is therefore lighter than air. However, it is freely mixable in air and therefore won't "settle" any more than salt water will settle if poured into a bucket of fresh water. Not to mention, how is carbon monoxide formed. In almost every case carbon monoxide is formed by the partial combustion of a hydrocarbon. That partial combustion generally release is a large amount of heat and therefore the carbon monoxide would be even less dense following the typical gas laws that as temperature increases volume increases and density decreases.
The other problem with carbon monoxide is one of affinity. It does not take a large concentration of carbon monoxide to lead to problems because the hemoglobin molecule binds carbon monoxide much more tightly than oxygen. Hemoglobin will bind the carbon monoxide and then only very slowly release it. As a result hemoglobin is no longer able to carry oxygen to the cells. Ultimately what happens with carbon monoxide is that the organs die for lack of oxygen. You can think of it almost like carbon monoxide is like a sticky form of argon. Argon is not a poison however if you breathe pure argon you die because you cannot get oxygen to your blood.and ultimately to your cells. If you take one big breath of pure argon then on the next breath you breathe normal air there won't be a problem. But if the argon had the ability to stick in your lungs then on the next breath the oxygen still wouldn't get in and you would end up suffocating. There is no lack of blood pressure necessarily nor is there any lack of blood flow it is simply that the blood being supplied to the organ is not carrying oxygen. Functionally it would be like replacing all the persons blood with salt water. For a short few seconds the heart would pump that salt water around but the organs would not receive any oxygen and therefore would die fairly rapidly. Is interesting to look at the treatment of carbon monoxide poisoning. If one is placed in pure oxygen then the mathematical probability of any oxygen atom bumping into the hemoglobin molecule during the time that it is in the lungs goes up by a factor of 5. (Going from a concentration of approximately 21 percent up to 100 percent) likewise going into a hyperbaric chamber at one atmosphere of pressure will double that mathematical probability even over pure oxygen. There is also a slight benefit to hyperbaric oxygen in that it causes more oxygen to be dissolved into the liquid phase of blood completely separate from hemoglobin itself.
It isn't in this post specifically but I noticed a posting somewhere else about the possible explosion hazard of carbon monoxide. Carbon monoxide is definitely combustible(autoignites at 630C) however it would be extremely unlikely for it to explode or readily burn at room temp. If you think about it, a catalytic converter is an "engine" designed to burn carbon monoxide! It uses rare earth metals as catalysts to allow the combination of carbon monoxide with more oxygen producing carbon dioxide. Ultimately the catalytic converter is fully burning the carbon atom which ultimately started as a hydrocarbon.
The other factoid about carbon monoxide that I like is the concept that it is an "odorless" gas. Certainly this is technically true that carbon monoxide as a pure gas doesn't have any discernible odor however in almost every case when carbon monoxide is being produced it is being produced because of inefficient combustion. That inefficient combustion almost always yields hydrocarbon fragments as well. Hydrocarbon fragments tend to give off an odor. So although it is true that carbon monoxide itself has no odor, the friends that it keeps typically do. If there is a case where the combustion is just inefficient enough to produce carbon monoxide but not hydrocarbon fragments then you will get and odorless gas. This is almost like saying that natural gas is odorless. Technically it is but when it is produced it is mixed with hydrogen sulfide to give it a discernible odor. Therefore natural gas does have an odor because natural gas in the most common state has been given an odor.
I had seen another posting talking about cyanosis associated with carbon monoxide poisoning. I believe I saw someone respond already that the color changes not cyanosis but rather a cherry red color. I've seen a number of carbon monoxide poisoning cases however I can't really say that I ever was able to notice this color difference. These were in cases with laboratory verified toxic levels of carbon monoxide. I read it in all the textbooks and I would answer it on a test question but I can't say as though I've ever actually seen it.
It was a very interesting discussion to be sure
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It is for gases though (to a good approximation)
Maybe beryllium is gaseous on your planet ? It would work then.
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Andy Dingley wrote:

I was about to mention the same thing. :-) ...lew...
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One other nasty thing about CO that I didn't notice anybody mention is that the hemoglobin in your red blood cells with preferentially absorb CO rather than O2 if CO is present. That's part of the reason it's so toxic. It locks up your hemoglobin and you suffocate for lack of O2. But it's also an anesthetic (as is CO2) so you just fall asleep. I've been a runner forever (well since 1961 - close enough). Back in the 70's when I used to smoke a pipe, I noticed I just didn't seem to have as much energy the next day. Turns out it takes ~36 hours for CO to equilibrate out of your hemoglobin when there is no CO present in the air. One pipe full of tobacco and I was probably 5% impaired. Pretty scary. That's why they treat CO poisoning with pure O2, they're trying to get the hemoglobin to let go of the CO.
Bottom line, be very careful around any source of CO. You could end up dead and never know it.
Jim
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in message

Ya, Jim, I'll be careful. tomorrow. I begin setting up a new meat packing machine that uses a VERY small dose of CO in the inerting gas which fills the package after the air has been vacuumed out.. I've insisted that the mixer and supply bottles be stored in the open air. All connections in the factory will be welded stainless steel.
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In some places that would not be considered sufficient.
Consider a vented toxic gas cabinet, and double-walled tubing, with the outer space vented and exhausted.
At the least, leak check all the connections before using it, and consider the drill when changing cylinders. CO detectors too?
The only reason I mention this is that a co-worker got a whiff of arsine gas at a plant at one time. The cylinders were stored in a vented gas room, but both belts had broken on the exhaust fan, *and* the regulator had been installed such that there was a tiny leak. He went in the room and though, hmm, something smells like garlic...
The damage was fortunately small and he recovered.
Jim
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Roy wrote:

Air is a mixture of about 80% nitrogen (molecular weight approx. 28) and 20% oxygen (molecular weight approx. 32). Carbon monoxide has a molecular weight of approximately 28. So it's very slightly lighter than air.
That only matters for a short while, though. Because it won't be too long before the gases mix thoroughly, regardless of their densities. How long is hard to say. You can calculate the time for perfectly still gases, but it's drastically reduced when the gases are stirred up even a little bit, as they are by people moving around, changes in barometric pressure, etc.
John Martin
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Leo Lichtman wrote:

Entropy.
John Martin
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It is slightly lighter than air. It also enters the blood stream around 300 times easier than oxygen, IIRC from my medical training.
If you suspect you or someone is affected, look at their nails. Cyanosis, bluing of nailbeds and lips, is a sign.
As another poster said, get a good CO alarm. This is one that has a constant digital readout of what the CO is at any moment, as well as a memory. If the danger level is 400ppm, I don't want to wait until then. Or if it only goes up to 396, and the alarm doesn't sound. By then, you will have a doozy of a headache, and feel bad for a while.
CO is lethal and kills people every day. One of the things that makes it so lethal is that it is silent and odorless. Get a good detector. I have Kidde brand.
Steve
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Interestingly this is absolutely untrue.
CO poisioning exhibits itself as nail beds, lips, etc as being bright cherry red.
Carboxyhemolglogin is every bit as red as the oxygenated variety - even more so.
In fact this is a strong indicator of CO exposure.
Jim
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wrote:

Jeezus..Jim got something right for a change...fuck me running!
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wrote:

That's usually a sign that they're already dead (or good as). CO is hazardous enough that it has a good chance of killing long before visible signs are evident. And for that matter they'll turn a deep pink from CO, rather than blue.
For chronic low-level CO exposure, a slight headache might be all the symptomatic indication you get. Then one day the wind is blowing the other way down your gas heater flue and you wind up dead instead. Back in the days of individual room gas heaters (coal gas) we really did lose an awful lot of people to these accidents.
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Andy Dingley wrote:

(snip)
In my practice of yoga I occasionally induce syncope (fainting from low blood pressure). Most yogis do not practice this way. It seems about a 50% reduction of blood pressure and associated (unknown %) reduction in flow to the brain can induce a loss of conciousness. What is happening is the brain is continuously metabolizing oxygen at about 20 watts, so it just sucks the oxygen right out of the blood, and metabolism stops.
The way this is relevant to the thread is that it's a timed effect. One cannot sustain induced syncope for long. However, with exposure to CO and so the blockade of O2 capacity, the blood carries and delivers less O2 to the brain for a long time; as long as it takes for the CO to respirate (diffuse, ventilate). More CO in the circulating blood, less capacity to deliver O2. 9 pints of the red stuff, and I think less than one gram of circulating O2 or CO, maybe on the order of a milligram.
Let's see 20 respirations per minute, is it about a liter each or five liters? So that's 1 or maybe 5 moles per minute. Around 40 or 200 grams per minute; 20% is absorbed. So a flow of 8 or 40 grams per minute. Back to volume that's a regulator flow of, er, the square root of three times the cosine of Ethiopia, I'd say.... :)
Circulation of 9 pints takes of order a minute or maybe 10 minutes, but I am so uncertain about that, why continue?
Argon/CO mix used for TIG welding steel is particularly hazardous. Argon displaces O2 in free air, CO displaces O2 in the blood.
I write much of the above from a careful study of recreational N2O use. Ever hear of Olney's lesions? Brrr. That's another topic. The only use of N2O in metalworking I know of is with butane in small Sparklets. 8 gm size; one of these of pure CO, inhaled, and held, would likely end one's life, but the standard suicide warning would apply:
What If It Just Gave You a Headache? Brrrr.
Is it called producer gas, the low-value mix of CO and H2?
Doug Goncz Replikon Research Falls Church, VA 22044-0394
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snipped-for-privacy@aol.com wrote: [snip]

That's "water gas": "producer gas" is basically air, with the oxygen replaced by CO.
Producer gas is "produced" by burning coke in insufficient air: the process is exothermic, so self-sustaining.
Water gas is produced by reacting steam with incandescent coke: this process is endothermic. H2O + C = H2 + CO. Typically water-gas generators are installed in pairs: one generates the gas, while the other gets a blow of (excess) air, so re-heating the coke. Then they swap roles.
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Steve, Are you sure about the cyanosis? I was always taught that the first indication of CO poisoning was a red face, as the haemoglobin soaked up the CO preferentially and the reduction in oxygen content in the blood causes increased circulation to compensate. I was raised in Canada, and it was a common cause of accidental death in the winter. A car would get stuck in the snow,and the occupants would leave the car running to keep warm . If the wind was blowing from behind the car,exhaust fumes would enter the car through air ducts and kill the passengers fairly quickly.
Tom
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