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Icon Of Sin posted:If you never got tired of it, your name was probably Thomas Klapötke
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Nov 9, 2017 18:27
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Mustached Demon posted:Destroyer of jeans?
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Nov 9, 2017 19:03
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LogicalFallacy posted:Okay, let's be honest here. That man probably doesn't even blink at explosions anymore. He probably responds to destroying yet another fume hood by shrugging and calling the budget department again. There's got to be a sign in his building that's along the lines of "must have -x kJ/mol to be studied"
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Nov 9, 2017 19:27
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So how long do you think it'll take him to synthesize N60?
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Nov 9, 2017 19:28
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iospace posted:So how long do you think it'll take him to synthesize N60? Probably 5 or 6 destroyed spectrometers.
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Nov 9, 2017 19:30
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iospace posted:So how long do you think it'll take him to synthesize N60? That's his white whale. Always edging closer to both creating that molecule, and to madness. Unsurprisingly those 2 things go hand in hand.
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Nov 9, 2017 19:38
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Icon Of Sin posted:If you never got tired of it, your name was probably Thomas Klapötke He's got ways of saying it that we mere mortals can't even tell the difference between. He hasn't grown tired of it because he must know all the different ways it can happen.
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Nov 9, 2017 19:45
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The face of a man who likes explosions and he cannot lie He's deaf as gently caress of course.
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Nov 9, 2017 19:48
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aphid_licker posted:The face of a man who likes explosions and he cannot lie In Britain this man would be wearing Adidas and harassing people outside a corner grocery store. In Germany he gets government funding to play with nitrogen.
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Nov 9, 2017 19:56
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have you guys seen the stop motion video IBM made with xenon atoms and a scanning tunnelling microscope? https://youtu.be/oSCX78-8-q0
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Nov 9, 2017 20:13
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I'm glad there is a place capable of unleashing his true gift to humanity.
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Nov 9, 2017 20:13
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Humbug Scoolbus posted:And leg hair! And, I suspect, given the chance, legs.
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Nov 9, 2017 20:32
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Here's a silly chemistry question. So water is ~18g/mol. CO2 is ~44g/mol. If you have 1L of pure water in a bottle, and 1L of carbonated water in a bottle, does the latter weigh more from the CO2 dissolved in it?
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Nov 9, 2017 21:01
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Segmentation Fox posted:Here's a silly chemistry question. Those two values are entirely useless for the question you are asking. First of all, to compare the masses of the same volume of two pure substances, for instance water and CO2, you're going to need to take the molar mass, and divide it by the molar volume (the volume one mole takes up) of the same substance. That way you end up with the amount of grams per liter, known as the density of the substance. For instance, water has a density of almost exactly 1 kg per liter (at room temperature), while carbon dioxide gas has a density of only 1.977 g per liter. You already know that gases are lighter than liquids so that makes sense. In other words, one mole of CO2 takes up WAY MORE SPACE than one mole of water. That's why you can't just compare g/mol to decide which is 'heavier'. Now the question is, does carbonated water weigh more than pure water? Well, what state is the CO2, when it's dissolved? Is it still a gas? Is it a liquid or a solid? Well, in fact, it's not quite any of those, because when CO2 dissolves in water, part of it reacts with water molecules to form carbonic acid, which rather complicates the matter. The rest of the CO2 just remains as dissolved molecules. It's really surprisingly hard to find good experimental values on this, but as far as I can tell, the net effect is that while the CO2 would make the solution less dense (lighter), the carbonic acid molecules somewhat attract the water molecules around it, squeezing them tighter together, and fitting more molecules in the same volume. So the net effect seems to be that it's ever so slightly heavier than pure water because of this attractive effect. But I'm not in fact 100% sure on this, and it might even depend on the specific amount of carbonation. E: BTW there's also the SAL chemistry thread for any general chemistry questions. https://forums.somethingawful.com/showthread.php?threadid=3283822&pagenumber=79#lastpost Carbon dioxide has a new favorite as of 21:38 on Nov 9, 2017 |
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Nov 9, 2017 21:34
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Carbon dioxide posted:Those two values are entirely useless for the question you are asking. You couldn't ask your acid cousins for how they interact with water?
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Nov 9, 2017 21:44
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Sound username/post combination.
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Nov 9, 2017 21:45
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Just weigh it lol
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Nov 9, 2017 21:55
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Step 1: Get a bottle of seltzer water for like, 58 cents at your local grocery store Step 2: Mark the carbonated water level Step 3: Weigh it. Step 4: Open the bottle and let the carbonation escape Step 6: Weigh it again Step 7: Mark the uncarbonated water level Step 8: Measure the circumference of the bottle at the water level You now can calculate both the change in volume and the change in mass. From there, you can determine whether the density was higher or lower than uncarbonated water. Tunicate has a new favorite as of 22:23 on Nov 9, 2017 |
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Nov 9, 2017 22:19
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Gases in water at Henry's law solubilities are very well described by ideal equations of state. Don't ask me which equation of state or how to solve it, I just remember the ideal is so good at it there's really no need for a table of values or anything CO2-Water system specific. E. Spoiler it works so well because it's like 200ppm of a gas, it ain't doing poo poo to bulk characteristics unless you got some very precise needs. zedprime has a new favorite as of 22:23 on Nov 9, 2017 |
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Nov 9, 2017 22:20
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Tunicate posted:Step 1: Get a bottle of seltzer water for like, 58 cents at your local grocery store This method won’t give you nearly enough precision to make any conclusions.
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Nov 9, 2017 23:10
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I could uh... do a very hacky method of that at work. Fill a cup full of carbonated water and another cup of regular water and weigh them out. Obviously it's entirely not precise but could give a good idea.
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Nov 9, 2017 23:15
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iospace posted:I could uh... do a very hacky method of that at work. Fill a cup full of carbonated water and another cup of regular water and weigh them out. The trouble is that "carbonated water" is actually supersaturated, which is why the carbon dioxide bubbles out of it. Ordinary tap water is usually saturated with it, so you'd need to boil it or sparge nitrogen through it to get rid of it before measuring. Turns out it's a really complicated and difficult measurement to make, and the density difference is probably quite small.
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Nov 9, 2017 23:18
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You can’t just pour a cup because carbon dioxide comes out of solution readily and any bubbles formed are an order of magnitude more significant than the change in volume you’re trying to measure. You need to use equipment more advanced than a kitchen scale and do all measurements under pressure to keep the carbon dioxide in solution. Platystemon has a new favorite as of 23:38 on Nov 9, 2017 |
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Nov 9, 2017 23:25
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Get Champagne. Down it. Weight yourself. Burp. Weigh yourself again. Problem solved. e: Remember you forgot to weigh the bottle. Get more. Go to first step.
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Nov 9, 2017 23:29
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Ola posted:Get Champagne. Down it. Weight yourself. Burp. Weigh yourself again. Problem solved. 
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Nov 9, 2017 23:31
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Maybe you could measure the pH of the water, attribute all of that to carbonic acid and then calculate the carbon dioxide, carbonic acid, bicarbonate and carbonate concentrations from that, and determine molarities and added mass when compared to a normal air equilibrated water. Probably closer than literally trying to weigh the difference anyway?
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Nov 10, 2017 02:02
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I found this on another forum which seems to answer the question.quote:I ran simulations, using the Sour PR (Peng Robinson) and Sour SRK (Soave Redlich Kwong) equations of state. (Standard simulations used by chemical engineers to predict CO2 and H2S removal) Because the CO2 will react slightly with the water, it's net effect is to draw the water molecules together a bit, giving it a tiny boost in density (about 1 g/l). Nitrogen just takes up space and reduces the density infinitesimally (about 0.04 g/l).
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Nov 10, 2017 02:13
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Deteriorata posted:I found this on another forum which seems to answer the question. Huh, well I certainly learned something today. Thanks.
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Nov 10, 2017 02:29
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Platystemon posted:This method won’t give you nearly enough precision to make any conclusions. Hmm... how precise could we actually get it? Let's actually enhance our precision a bit by only dealing with a relative change. Do it analog by adding decarbonated fluid into the flat bottle until the mass is equal to the original amount. Since a drop of water is less than 1 ml (and hence less than one gram - at room temperature it's 0.9970 g/cm^3), and there are about 12 grams of CO2 within a 2 liter bottle, I'd say it's a reasonable assumption that (with steady hands) you'll be able to match the original mass within +-1 gram. That gives an error bar of our final fluid volume due to weighing out wrong the mass of +-0.05%, give or take (since it's 1mL / 2ish L). That's about the best you can expect using a kitchen scale marked in grams. So... other constraint is the height of the fluid. The starting fluid level is usually in the neck of the bottle, where it's thinner. Let's use a bottle of sprite instead, since it has that nice cone to make the cross-section small  50 pixels wide there, compared to 117 pixels wide at the roundest point. Standards for 2L bottles are at 101.5 mm diameter for the widest point, so 43.3 mm wide at the liquid level. The area is pi*43.3^2 mm^2 at that point. It's a 2 liter bottle of drink, so we'd expect a 1% change in density to correspond to 3.4 millimeters up or down (well, a bit more or less because it's a cone, but close enough). You can probably eyeball a couple mm of difference. If we started off with a laser pointer barely skimming the top of the liquid (and managed to keep the setup from moving at all), we could probably get down to submillimeter precision for the 'up or down' question, which might get us able to detect the direction of a quarter of a percent change in density - not an exact amount, but enough precision to answer 'did it go up or down' within 0.25%. Good luck keeping a laser pointer and bottle perfectly stationary though. Cheating a bit, according to Density of aqueous solutions of CO2 it's theoretically possible to get a 2-3% change in density from saturated CO2 in an aqueous solution compared to pure water. I don't know how close to the maximum soda is compared to what they're dealing with, but in principle you could definitely detect a change in density due to CO2 in some kind of aqueous solution. So... yeah, you might be able to kitchen counter science this. Tunicate has a new favorite as of 02:38 on Nov 10, 2017 |
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Nov 10, 2017 02:33
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I think one problem you’re going to run into is that the PET bottle deforms a non‐trivial amount (on this scale) under pressure. A glass bottle might work better.
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Nov 10, 2017 06:09
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Did you put a 250 ml bottle on a top loading balance yet?
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Nov 10, 2017 07:28
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Deteriorata posted:I found this on another forum which seems to answer the question. Yeah, this is the most reliable source (as in it looks like they've done their homework) I could find after a quick google search, and it is what the result of my post is based off of. The problem is that there are plenty of other sources saying something else, which is why I wasn't sure. Tunicate posted:
Woah woah woah don't just skip over this! You post a paper that seems to directly answer the original question and don't even dive into it. The paper contains actual measurements. "Quote: A maximum density increase of 2.5 % is obtained for a solution with a CO2 mole fraction of 0.05 [at 100 bar]." It doesn't really clarify this but I'm assuming this increase is the increase relative to pure water? Well, they're measuring it at high pressure which I suppose makes measurements a lot simpler. At that pressure, there's a density increase so it's actually 2.5% heavier than pure water. The calculated result Deteriorata posted is at 55 psi or about 3.8 bar, which is much closer to what we'd find in the wild* has a density increase of about 0.1%. I would expect there to be still a density increase at these lower pressures, but not nearly as high as the 2.5%, so the 0.1% finding could make sense. It also could be the case that that calculation is missing some details and the real value at atmospheric pressure is somewhere between the 0.1% and 2.5%. But at the very least we got it down from "no clue" to a rather small range. * 1 bar is close to atmospheric pressure, internet tells me a can of coke has somewhere between 1.5 - 2.5 bars Carbon dioxide has a new favorite as of 07:33 on Nov 10, 2017 |
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Nov 10, 2017 07:31
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Carbon dioxide posted:Yeah, this is the most reliable source (as in it looks like they've done their homework) I could find after a quick google search, and it is what the result of my post is based off of. The problem is that there are plenty of other sources saying something else, which is why I wasn't sure.  He starts in imperial, and goes out to four digits of sigfigs, and ends up further off than if he just assumed water was universally 1 g/cc. It's irritating me way more than it should! Carbon dioxide posted:Woah woah woah don't just skip over this! You post a paper that seems to directly answer the original question and don't even dive into it. The paper contains actual measurements. "Quote: A maximum density increase of 2.5 % is obtained Just doing a literature search is *way* too much like actual work.
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Nov 10, 2017 07:55
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aphid_licker posted:The face of a man who likes explosions and he cannot lie I was slightly disappointed when I first saw his picture because I have always imagined him looking like Dr. Strangelove.
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Nov 10, 2017 11:46
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Tunicate posted:My biggest irrational problem with that source is that their density of water is off by about a percent. Water doesn't get denser than 1g/mL in atmosphere - so if he's using 1.008 he's got his water under a hell of a lot of pressure Deep-water oceanography runs into the same issue. Eventually the pressure down below gets so great that it can actually compress the water slightly, and this has an effect on temperature readings from instruments (I think from more water molecules physically being in contact with the thermometer?) that has to be corrected for. I want to say it was somewhere around 3,000m of depth that that effect started coming into play.
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Nov 10, 2017 13:35
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Icon Of Sin posted:Deep-water oceanography runs into the same issue. Eventually the pressure down below gets so great that it can actually compress the water slightly, and this has an effect on temperature readings from instruments (I think from more water molecules physically being in contact with the thermometer?) that has to be corrected for. I want to say it was somewhere around 3,000m of depth that that effect started coming into play. I think I remember it being under the carbonate compensation depth, which is 4200-5000m depending on the temperature and acidity of the water. It's been a lot of years since I took Oceanography so I could be wrong.
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Nov 10, 2017 13:42
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Is this FOOFy enough?quote:To instantly generate a megawatt of power, TRW's Alpha chemical laser would mix hydrogen and fluorine gas together much like a liquid-fueled rocket engine does. Light and heat from the the resulting reaction would then be converted into laser light and sent to a primary mirror wider than the one aboard the Hubble Space Telescope. Complex sensors and computers would track targets and aim the weapon's laser beam. http://nationalinterest.org/feature/zenith-star-the-space-laser-won-the-cold-war-14481
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Nov 10, 2017 17:36
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Memento posted:I think I remember it being under the carbonate compensation depth, which is 4200-5000m depending on the temperature and acidity of the water. It's been a lot of years since I took Oceanography so I could be wrong. I remember it being somewhere around in there, maybe between the silcate and carbonate compensation depths? Note for everyone else: those are both weird in that their solubility increases with depth and their compensation depths are always at/near the same depth, so we use them as a historical marker for where a certain depth was (and by extension where the sea level was) at a given point in geologic history.
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Nov 10, 2017 17:45
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Tunicate posted:My biggest irrational problem with that source is that their density of water is off by about a percent. Water doesn't get denser than 1g/mL in atmosphere - so if he's using 1.008 he's got his water under a hell of a lot of pressure I swear this is a standard intro to Pchem question so it's surprising there aren't more homework help answers when googling. I remember it being as easy as using Henry's law for concentration (still, source of error one CO2 gets more soluble than Henry's would say from the acid reaction but it's close enough for soda water I think) and then using some sort of ideal or water focused EoS (source of error two, the acid bit being less than ideal).
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Nov 10, 2017 18:06
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I LICK APE PUSSY posted:Is this FOOFy enough? Oh yes it is.
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Nov 10, 2017 19:16
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