If I were to put a ton of CO2 in a balloon and put it on a scale, would the scale indicate a ton?
Peace,
mangeorge
Yes.
Plus the weight of the balloon. 
Usually in this case, “ton” means “mass ton”, as opposed to “weight ton”, so no.
Hmmmmm. One yes, one no.
I’m going with the yes guy. In orbit the balloon would have no weight, but would still mass a ton. Sitting on the bathroom scale in your house at 1 g it would weigh a ton.
Or so I’m thinking, but I’m often wrong about these things.
Boyancy would make that not true. Carbon dioxide is denser than air, but not by a whole lot. When it comes to something about as dense as water, boyancy in air is negligent. But carbox dioxide would have significant boyancy. Imagine a ton of helium. It would show up as negative on the scales, even though gravity is putting a ton of force on it.
Unless your bathroom contains a vacuum, there’s buoyancy to account for. If the balloon + CO2 masses a ton, it will weigh less by the difference between the mass of the balloon and the mass of air it displaces.
That would only be true if the the balloon was fairly big. Put a ton of helium in a balloon a few meters across and it ain’t gonna float worth squat.
A mass ton under 1 g is still a ton, I think.
What I want to know is, when people say they are creating or saving 16 tons of carbon, what does that actually quantifiably mean? Is it a lot? Is it only a little bit? Is it the equivalent of destroying a quarter acre of rainforest? What???
It’s a meaningless statistic without context. You may as well say you rotated a metric assload of oxygen.
I considered buoyancy. Unless you had special circumstances, however, a ton of anything in a balloon is a lot. It would lie flat against any scale.
I suppose if you had some sort of skyhook that measured the weight of a dangling balloon, bouyancy might come into play. Failing that, an ordinary scale located on earth, large enough to rest the balloon on, should read the weight of the system pressing against it. You might have a tiny effect from air pressing against the sides.
The problem is that the OP didn’t define the system at all. If everybody responds with a different conceptual system, then it’s true we can get differing results. Is the scale otherwise in a vacuum? Is it an ordinary bathroom scale? Does the balloon rest on it or hang from it? Are the temperature of the gases inside and out at equilibrium?
Are we even on earth?
Well, I was imagining the balloon would expand such that the pressure inside stays roughly the same as outside the balloon. That’s how all the balloons I’ve ever played with work. But yeah, if you put enough pressure on it to increase the density beyond that of air, it would show positive on the scales, though boyancy would still be significant as long as it’s a gas.
No. Density of air at sea level is 1.2 g/L. Density of CO2 is 1.98 g/L.
A “mass ton” of CO2 is 907.2 kg, displacing 458,182 L worth of air. The displaced air has a mass of 549.8kg.
So if you were to put the balloon on a scale, it would weigh 907.2-549.8=357.4 kg (787.9 lbs), plus the weight of the balloon material.
So a “mass ton” of CO2 only weighs 0.4 tons.
Quoted for truth.
:dubious: I think you should rethink this statement. Or start a thread titled “How do balloons work?”
Obviously, if the gas is compressed it changes everything. However, that’s one highly-rigid “balloon.”
No, I didn’t. Sorry.
I saw a commercial comparing the CO2 emissions of a SUV and a house. In tons.
Earth house, earth SUV. 
Free (uncontained) CO2.
So, what the hell are they talking about?
Uhh… Have you ever tried to blow on a tire gauge? How about blowing up a tire with your mouth? Humans are capable of blowing very little pressure, I’m guessing less than 1 PSI. If balloons did hold a lot of pressure, you wouldn’t be able to blow them up with your mouth, like tires. Of course I’m talking about party balloons, not hot air balloons, blimps, or anything like that.
If what’s in the balloon is helium or hydrogen, it will not lie flat against a scale.
Why would a balloon resting on a scale see buoyancy effects different from if it were dangling? The buoyance is due to the surrounding atmosphere - it has nothing to do with how the balloon is supported.
Getting back to teh OP as restated in post #14 …
Per YamatoTwinkie, a ton of CO2 is very roughly 500,000 liters (at STP). That’s a cube about 25 feet on a side.
Given that the CO2 concetration in ordinary air is about 0.03%, or 3 parts per 10,000, that means a ton of pure CO2 is about as much as is found in a cube of ordinary air very roughly 350 ft on a side.
So qualitatively, a ton of CO2 is very very roughly enough to double the CO2 concentration of the interior of a smallish US shopping mall with a couple anchor department stores.
Caveat: All these figures were done ballpark & with rounding & simplified conversion factors, so the final result is probably off by 10-20% (+/- any exponent errors I made).
They are talking about a mass ton of CO2–907 kg, as YamatoTwinkie says. A specific number of molecules, in other words.
Your additional question about the balloon and scale is interesting, and we could argue up some assumptions and calcualtions and conclusions and get a reasonable answer, but it’s really got nothing to do with understanding what a ton of CO2 is (or, rather, what the folks in the commercial mean when they refer to “a ton of CO2”)
A ton of CO[sub]2[/sub] has a mass of one ton, equal to 2,000 lb[sub]m[/sub], or 907.2 kg. At standard temperature and pressure (STP), (0 °C and 1 atm), and assuming ideal gas behavior, it would have volume of about 462,000 liters. This could fit into a large balloon with a diameter of about 9.6 meters.
As YamatoTwinkie and others have noted, due to buoyancy effects, the balloon will weigh less than a ton if placed on a scale. However, it will register a weight (correctly calculated by the aforementioned YamatoTwinkie). Several others in this thread do not appear to be properly accounting for buoyancy or understand how a balloon works. In any event, we are still talking about a LOT of gas.
Cubsfan, balloons with non-rigid walls do indeed have about the the same pressure as the air surrounding them. Small balloons with elastic walls do have a slightly higher pressure necessary to overcome the elastic force of the balloon, but larger balloons (including hot air balloons) with non-elastic walls have exactly the same pressure as the air surrounding them.
A ton of helium at standard temperature and pressure (0 °C and 1 atm) would have a volume of about 5,083,340 liters. You could fit this in a spherical balloon with a diameter of about 21.3 meters.
It would float just fine.
If you compress the ton of helium into a smaller container, you are not really talking about a “balloon” anymore. The smaller container would need strong, inelastic walls, resulting in something more like a compressed gas tank.