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Everything posted by jdurg
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One must also realize that the silver ion is actually moderately toxic and not something you want a lot of in your body.
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Indeed. In fact, with glass the decomposition of the glass is caused not by the F2, but the presence of HF. Glass isn't just crystalline Silicon Dioxide. It's an amorphous mass of many oddly linked molecules. What causes the trouble with fluorine gas attacking glass is when an -OH portion of one of these molecules interacts with the fluorine gas. F2 will readily attack -OH groups ripping the -OH group off and in the process creating HF. HF attacks silicon dioxide without any problems. So when the F2 hits the glass, if there's any water in the air then it will form HF which will attack the glass. When HF attacks glass it creates compounds which have a readily available H atom exposed. F2 will then attack that H atom forming HF which repeats the process. Theoretically, if you have glass made out of a single SiO2 crystal in a dry box with absolutely ZERO water molecules and 100% anhydrous F2, you could keep a sample of fluorine gas in a visible glass container. In reality, that's pretty difficult to do.
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Woelen, are you certain that the presence of the metal ions and/or the iodide ions won't catalyze the decomposition of the H2O2?
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Any Cl2 that forms would be a very miniscule amount and would most likely go on to oxidize any I- in solution to I2, so in a sense it would actually kind of help you out there.
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Alcohol and how it affects personality?
jdurg replied to jdurg's topic in Anatomy, Physiology and Neuroscience
Late reply by myself, but I turn 26 in a handful of months. -
LMFAO. I know this doesn't have anything to do with this thread, but that was priceless ed84c.
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Exactly. I actually first learned about the effects of Nutmeg in my toxicology class in college. The amount needed to create any type of hallucinogenic effect is just below the amount needed to kill you. In addition, any type of hallucinogenic effect created by nutmeg is typically of a morbid and depressing nature due to the INTENSE amount of pain a high level of the stuff will put you in. (With virtually all hallucinogenic substances, the experience is all dependent on the users "mood". If one is feeling happy and at peace, they tend to experience pleasant 'trips', so to speak. If one is in pain, depressed, hurt, or not feeling well those 'trips' just intensify the feelings that are making them feel bad. This leads to the higher rate of suicide in people who routinely take hallucinogenic substances). NOTHING good can come from a "nutmeg hallucination". Those who try and do it are just sad individuals. (On an interesting side note, the U.S. Navy bans the use of nutmeg on all of their ships. When my father was in the Navy on the nuclear submarines, he said that nutmeg was not allowed on board in fear that a sailor may purposefully, or accidentally, overdose on the stuff and go crazy on the nuclear submarine).
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Not likely. In fact, the presence of the vaccuum may cause the decomposition to occur more rapidly as the gases that are created would be dispersed much quicker pushing the equillibrium of the reaction further to the right.
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Yet another nice experiment - selenium allotropes
jdurg replied to woelen's topic in Inorganic Chemistry
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No problem. Yesterday I was just on a 'DEATH TO ALL THOSE WHO DEFY ME' phase and was on some type of mission to stomp out even the slightest incorrect information. Yeah, it is argon that has only been created as a compound with fluorine at insanely low temperatures. There's still some debate as to whether or not transfer of electrons has actually happened, however. (I tend to consider any simplified arrangement of atoms involving two or more elements where electrons are transferred from one species to another a chemical compound). So if the Argon transferred electrons to Fluorine I would consider it a chemical compound no matter how unstable it is. I guess that's what the researchers are currently trying to find out.
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Yet another nice experiment - selenium allotropes
jdurg replied to woelen's topic in Inorganic Chemistry
I've inhaled numerous amounts of H2Se and other selenium containing gases. I'm still alive and in quite good health. The supposed toxicity of selenium is a bit overdone, I'm afraid. And here's some data to back that up http://www.oehha.org/air/chronic_rels/pdf/selenium.pdf: In 1991 a clinical study was undertaken by 142 patients in western South Dakota who lived in areas where a great deal of selenium exists in the environment and large amounts of selenium were ingested. NONE of the subjects showed any clinical toxicity to selenium even though many of them had ingested amounts greater than 200 ug/day. The study goes on to show that intakes of up to 0.853 mg/day of selenium results in no toxicological findings. So the whole reason why there is no major hubbub over Selenium toxicity is because it isn't really toxic. Is it something you want to be ingesting like it's candy? No, but then again I don't know of anything that is. I've worked in labs where people constantly left the lab any time an aluminum compound was used, but does that mean that aluminum is the most horribly toxic thing on earth? No. They left the room because it was a crowded lab and the sodium aluminum hydride they were using required special care. As a scientist you should know that it's not a good idea to make assumptions without having a full set of data. The human body requires about 65 ug/day. Based on the VERY thorough study linked to above, up to 853 ug/day of selenium can be intaken without ANY toxicological symptoms being shown. That's a ratio of about 13.12 to 1. For Chromium, if my memory serves me right the suggested daily intake is about 100 ug/day, but toxicity begins to show at around 1,200 ug/day. That's a ratio of 12:1 which makes chromium the most toxic trace element that I have found. (Though I think that the fluoride ion takes the cake there). -
HF and F2 are two completely different compounds. HF doesn't oxidize much of anything, but F2 certainly does. The reason why aqua regia is able to dissolve gold is because while the nitric acid portion of it oxidizes the gold, the chloride ion is able to move in and stabilize the gold ion and pull it out of solution by forming AuCl4(-). This forces the equillibrium over to the right and allows more gold to dissolve. In HF there is nothing to oxidize the gold so it is unable to go into solution.
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Seeing as how gold will react directly with chlorine gas, bromine gas, and iodine gas it's pretty likely that it will react with fluorine gas as well.
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Yes, low pressures are required for the operation of a fluorescent light bulb as at normal pressures gases are simply too good of an insulator. You would need to apply a MASSIVELY high voltage in order to complete the circuit and that would be a huge waste of power and a VERY inefficient method. By using a reduced pressure gas, the electrons are able to move from one electrode to the other. In other words, at low pressures gases can conduct electricity at much lower voltages than are required at higher pressures. In fluorescent bulbs they also have a miniscule amount of mercury metal in there. The low pressure causes the mercury to vaporize which allows it to pass a current much better and also creates ultraviolet light when a voltage is applied across the electrodes. This UV light strikes the phosphors on the inside of the bulb causing them to fluoresce, hence the name "fluorescent light".
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Yes. A dosimeter is MUCH better than a little geiger counter. A dosimeter will take into account the type of radiation that you are exposed to and not just the fact that you have been exposed to it. A geiger counter is ONLY good for telling you that radiation is there. It will not tell you anything about the energy level of said radiation as a Geiger counter simply measure the occurance of a radioactive decay. A good analogy is the difference between having forty bullets in my hand and throwing them at you, then taking one bullet and firing it at you through a rifle. A Geiger counter would read those thrown bullets and click like crazy because there are forty of them that are hitting you. The truth of the matter is, those forty bullets aren't going to cause you any damage. When I take that one bullet, put it in my rifle and shoot it at you, the Geiger counter would only make one click. That one click, however, would kill you. A dosimeter is incredibly useful because it takes into account the energy behind each decay event. If you are in an area that makes the Geiger Counter go crazy but each event is of incredibly low energy, the Dosimeter will not be affected all that much. If you're in an area where the Geiger Counter isn't doing too much, but the level of energy for each event is very high, then the Dosimeter will start going nuts.
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But limewater is not a liquid. It's a solution of one thing dissolved in another. There are MANY solutions that react with air but are somewhat harmless to humans, but I do not know of ANY liquids (I.E. a pure substance) that reacts with air and is non-toxic/harmful.
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Heh. With most magnets, I believe that if you increase the temperature of the magnet to a relatively high level you disrupt the magnetic field by altering the arrangment of the atoms within the metal. Gadolinium is one of the few elements, I believe, that will regain its magnetism upon cooling down. Heating up an iron magnet will destroy the magnetic field, as will a sharp physical 'attack'. I.E. if you hit a magnet hard enough you'll disrupt the magnetic field and it will lose its magnetism.
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Well you know what the specific heat of water is (That's easy to look up) and you know the mass of water you started with at 25.0 degrees and the mass you started with a 60 degrees. Based on the standard data for the specific heat of water and the data you have there, you should be able to easily calculate the temperature of the water if no heat is lost to the surroundings. (I.E. a perfectly insuled calorimeter that doesn't absorb energy). Since you were given the final temperature of the water you'll be able to determine just how much heat was lost to the calorimeter and this should give you everything you need to determine the constant you seek.
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Not the modern ones. They quit using thorium oxide back in the late 1970's I believe.
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Well one thing is for certain, you are making a bunch of nitrogen oxides there because NOx's smell a LOT like bleach. Perhaps they are reacting with some other contaminant in the air, however?
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One thing to also remember is that a Geiger counter may go crazy and start crackling like crazy, but a Geiger counter only detects a decay event and not the strength of the event. If you have a sample that is decaying rapidly but giving off low energy emissions it is much less dangerous than a sample that decays a bit slower but emits higher energy radiation. The Geiger counter may make something seem like it is really "hot" and "dangerous", but in reality the energy being given off is incredibly small. I recently came upon this website which is the first site I've ever seen that breaks down a samples radioactive decay by the energy level of the associated decay. I had always heard of Uranium-238 decaying and giving off alpha and gamma rays with a decay energy of 4.xx MeV which is a pretty damned high number. I did NOT know, however, that the gamma energy given off by the decay is amazingly low. The alpha particles have the high energy and the gamma rays given off are pretty low in energy. I must say that DV8 2XL is correct in that the leaded casing is a bit of overkill for the storage of a depleted uranium sample.
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Yeah, I think a lot of that is psychological. We all know that fluorine is INCREDIBLY reactive and toxic, so when we see it our brain kicks in a bit of an alarm. A good analogy is nitroglycerin and vegetable oil. They both have the same yellowish, oily color to it, but when you look at a vial of vegetable oil you don't get nervous. When looking at a vial of nitroglycerin, however, your heart rate goes up a little bit and it "looks" more reactive.