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Fri 15 Jan, 2010 05:16 am
Hello there.
I saw this experiment, where a guy blew air into a balloon, wich of course is CO2, and then poured over liquid nitrogen. What was left was this very condensed liquid, and of course very cold, called "liquid oxygen"
But i've also heard that when CO2 changes from gas to liquid to solid, it becomes Dry Ice.
So how come CO2 or exhalation air becomes LOx when cooled down?
Quote:a guy blew air into a balloon, wich of course is CO2
No "of course" about it. Air is a mixture. Inhaled air is 78% nitrogen, 21% oxygen, 1% inert gas such as argon. Exhaled air has 78% nitrogen, 17% oxygen, 4% CO2, 1% inert gas such as argon.
Quote:So how come CO2 or exhalation air becomes LOx when cooled down?
It doesn't.
Thanks for the answer
But is there is still more oxygen than co2, how come a flame will stop burning? Oxygen aids the combustion, right?
@Mibro,
Combustion stops when CO2 is more than 10%
@contrex,
Ahh, ok, thanks for the answer!
@Mibro,
Blow air on hot coals and watch the coal glow brighter, up to that point where the air stream begins to cool the coal.
Heat oxygen and fuel are all required simultaneously. remove one the heat by blowing cool air on the surface of a hot coal and the combustion decreases.
@Mibro,
The air in the ballon is mostly nitrogen with some O2 and some CO2 added in as mentioned above. The liquid nitrogen being poured on the ballon is
vaporizing at around 75 deg K. If you look at a
phase diagram for O2, you see that you can get liquid O2 at that temperature, so it is feasible that you are seeing some liquid O2 coming from the ballon. The
phase diagram for CO2 shows that at that temperature and pressure, it will go straight to a solid, so it might be fun to cut open the ballon to see the dry ice.
I thought elements have three states, based on its temperature. Solid, liquid and gas. With less molecular movement (colder), the element eventually reaches its solid state; as the element heats up (more molecular movement) it first becomes a liquid, and eventually becomes a gas. Like water (works for inorganic compounds). Water is ice at its coldest, then water, and finally steam at its hottest state.
If I am wrong, I guess I did not learn my high school chemistry correctly?
@Foofie,
Foofie wrote:
I thought inorganic compounds have three states, based on its temperature. Solid, liquid and gas. With less molecular movement (colder), the compound eventually reaches its solid state; as the compound heats up (more molecular movement) it first becomes a liquid, and eventually becomes a gas. Like water. Water is ice at its coldest, then water, and finally steam at its hottest state.
If I am wrong, blame my high school chemistry that I thought I learned?
4 states - Plasma is the hottest. And there may be more states as well!
Cycloptichorn
@Cycloptichorn,
Cycloptichorn wrote:
Foofie wrote:
I thought inorganic compounds have three states, based on its temperature. Solid, liquid and gas. With less molecular movement (colder), the compound eventually reaches its solid state; as the compound heats up (more molecular movement) it first becomes a liquid, and eventually becomes a gas. Like water. Water is ice at its coldest, then water, and finally steam at its hottest state.
If I am wrong, blame my high school chemistry that I thought I learned?
4 states - Plasma is the hottest. And there may be more states as well!
Cycloptichorn
I never learned about plasma. When I went to school we were not even on the moon yet.
Why does it say Lox in the tags at the top of the page? Is there an offer for smoked Nova Scotia salmon embedded in this thread? How do i get mine?
This thread raises more quesitons than it answers.
@Setanta,
Setanta wrote:
Why does it say Lox in the tags at the top of the page? Is there an offer for smoked Nova Scotia salmon embedded in this thread? How do i get mine?
This thread raises more quesitons than it answers.
I thought Lox is Liquid oxygen? However, if it is the lox put on bagels then it would also need cream cheese. Philadelphia brand to be authentically "bagels, cream cheese and lox." And any coffee should be Maxwell House.
I will trade one bagel with cream cheese and lox for a plate of corn beef and cabbage. (Virtually of course in cyberspace.)
@Foofie,
Quote:I thought Lox is Liquid oxygen?
LOX, LOx or less frequently, Lox are abbreviations for liquid oxygen; lox with a small 'l' is a regional name (USA East Coast, and Canada mainly) for what the rest of the English speaking world calls "smoked salmon". The word lox is a Yiddish word for “salmon".
@Foofie,
It's slightly more complicated than that. Depending on the pressure, you don't have to go through the liquid state to go between gas and solid. Here is the phase diagram for water. At one atmosphere, you transition from solid to liquid to gas as you raise the temperature.
But if you look at the CO2 plot I posted above, you see how the line at one atmosphere goes from solid directly to gas. That is what happens with dry ice.
Gentlemen, responding to Foofie on an assumption that he has a normal understanding, is well educated or possesses a subtle sense of humor (or even a gross one) is always a mistake.
@engineer,
engineer wrote:But if you look at the CO2 plot I posted above, you see how the line at one atmosphere goes from solid directly to gas. That is what happens with dry ice.
This change from solid directly to liquid is called "sublimation".
Contrex wrote:This change from solid directly to liquid is called "sublimation".
Surely you made a typo, Contrex!
Francis wrote:Surely you made a typo, Contrex!
yes... blame it on a very nice Sancerre. Of course I meant "from solid directly to vapour"
@contrex,
contrex wrote:
Quote:I thought Lox is Liquid oxygen?
LOX, LOx or less frequently, Lox are abbreviations for liquid oxygen; lox with a small 'l' is a regional name (USA East Coast, and Canada mainly) for what the rest of the English speaking world calls "smoked salmon". The word lox is a Yiddish word for “salmon".
Ud. vive en Espana y sepa acerca de las comidas de los Judios? Increible!
@Setanta,
Setanta wrote:
Gentlemen, responding to Foofie on an assumption that he has a normal understanding, is well educated or possesses a subtle sense of humor (or even a gross one) is always a mistake.
Did you forget to include a high IQ?
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