"Ecnerwal" wrote in message
...
In article ,
(Roy) wrote:
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.
And you slept though Chemistry, saying "when will I ever use this boring
stuff..."
CO: 12+16=28, .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.
--
Cats, coffee, chocolate...vices to live by
CO 12+16=28 (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