woelen

Certain lanthanide oxides also are. These are not really toxic and also quite affordable, but I do not think you should put them in your food.

I have written an entire webpage on this reaction and started a thread about this: http://www.scienceforums.net/forums/showthread.php?t=19655 You obtain Mn2O7. This is VERY reactive and in the gas phase it is purple. Look at the webpage for some nice pictures of the stuff and a fairly detailed description of the chemistry behind this.

The name of that compound, I really don't know. Maybe phenyl-trioxide? But that is not really correct, because phenyl is a C6H5- group, and here we have a benzene-ring with all the hydrogens removed. A better name probably would be trioxo-benzene, analogous to something like trichlorobenzene. With trichlorobenzene you have to say where the chlorines are on the ring, hence you get something like 1,2,3-trichlorobenzene, or 1,2,4 trichlorobenzene (these are two possible isomers, there are more, however). With the oxo-compound, there is only one, so no need to use prefixes, telling where the oxygens are. But, to be honest, I'm not sure about these names. Maybe an organic chemistry specialist can tell more about this.

Moderator action: moved to pseudoscience. This is one of MANY MANY claims about relativity being wrong. This does not belong in the science forums. Feel free, however, to continue discussion and posting over here.

There are many reasons why a certain compound cannot exist. Although indeed that compound C6O3 has a valid benzene aromatic ring and the oxygens have two bonds, it probably cannot exist for steric reasons. How do you imagine this molecule to look like in reality? Where would the O-atoms fit in the molecule? The structure you have drawn seems to me one with extremely long bonds between the O-atoms and C-atoms and I expect a very high strain in this molecule. So, in general, a molecule can satisfy all bonding rules, but if it cannot be realized sterically, then still it cannot exist. E.g. CI4 (tetra iodo methane) does exist, but it is quite unstable, because the molecule is really crowded with the big iodines around that small C. The compound C2I6 (hexa iodo ethane) does not exist, it would have such extreme bond strains that simply one of the iodine atoms snaps off the molecule and the molecule breaks apart. Think of the bonds as mechanical springs. A spring does not like to be pressed, nor to be stretched. When it is pressed into a shorted length, then it pushes back, if it is stretched, then it pulls back. If it is pressed too much, or stretched too much, then it breaks into parts and is destroyed. This is exactly what happens with the bonds. These also have a preferred length and shorter or longer bonds (or strongly bent bonds) feel strain. When the strain is too large, it breaks apart, just as the mechanical spring.

I would be very careful ordering complete pyro products. Pyro chemicals already are suspicious nowadays, but complete devices are really suspicious (at least in the country where I live). From that same site as YT ordered some stuff, I already ordered three times and I must say that their chems are no problem and I always got what I paid for, with fast shipping times (communication about order status could be better though). I'm quite sure, however, that ordering complete fuses would be a whole different thing for me, then I would really be afraid of getting the parcel through customs. So, next time, you'd better make your own fuses. More work, more hassle, but less suspicious. Of course the different chemical constituents you then have to purchase from different suppliers. E.g. I never order oxidizers and reductors at the same time, and of I ordered oxidizers at one suppliers, then I'll certainly look for an alternative supplier for reductors. It is sad that we have to do this kind of things, but it be so.

Another nice demo is the separation of a mix of iron powder and sulphur by means of a magnet. Then you mix the iron and sulphur again, put it in a test tube and heat it. At a certain point, the reaction proceeds on its own, giving a dull red heat. The iron sulfide formed cannot be separated anymore. Your mix of iron and sulphur is changed into a new chemical compound. This experiment can be done in 10 minutes, and it only requires very common chemicals like iron powder and sulphur powder. Only coarse powder is needed.

Go out to a pottery/ceramics shop and try to obtain some cobalt carbonate, and dissolve that in dilute nitric acid, as [w00t] suggested. Many pottery shops also have cobalt sulfate, which is a soluble cobalt salt and I'm quite sure that is as useful as cobalt nitrate, but much easier on storage (it is not hygroscopic). Do not use the cobaltosic oxide from pottery stores, Co3O4. This stuff is remarkably inert. I have some, but I could not dissolve it in any acid I have, not even boiling hydrochloric acid, with a reductor present in order to convert the cobalt (III) in the cobaltosic oxide to cobalt (II). The carbonate, however, with the help of some moderate heating, nicely dissolves in dilute mineral acid.

Of course they are able to help you, but these are really basic things. You should be able to find out yourself. But... you're lucky. I had a good day and will try to give you some hints which may help you . Just a simple hint: All questions of (4) boil down to integration of all separate terms and adding these indefinite integrals together. You just need to know the primitive functions for all of these. I'll give you one of these. g(x) has two terms, one being 19/x, the other being 15x². you need to know the primitives of 1/x, and of x². These are (for x > 0), ln(x) and ⅓x³ (and having a non-determined constant term). Multiply with the factors 19 and 15, and you find your answer: 19ln(x) + 5x³ + C, where C is a indefinite constant. For integration of h(u) you need to write sin²(u/10) in terms of cos(u/5), and then you integrate the function. You only are left with a cosine without higher powers. Question © seems really trivial to me, I do not see why you can't solve that. Question 6a: sin(3x)dx/(2+cos(3x)) = -⅓*d(cos(3x))/((2+cos(3x)). Use a change of variable z = cos(3x) and your integral becomes simple again. You only need to integrate 1/(2+z). Questoin 6b: Use a similar trick as in 6a. (exp(-x) - exp(x))dx = -d(exp(x) + exp(-x)) Now use a change of variable: z = exp(x) + exp(-x). Your differential equation now becomes: dy = (-4√y * dz)/z² This should not be difficult to solve anymore.

Neutrino's are not easily made. Making them requires high energy nuclear processes. Neutrino's are very elusive particles. They are very light (or even massless??) and they have VERY little interaction with the matter, we know. They are made inside the sun, where nuclear fusion is the source of energy. Neutrino's definitely are not made by chemical processes.

Pure rust is not black, but brown/red. I think that the foam at the surface indeed contains rust (or better: ferric hydroxide). The lower black precipitate undoubtedly will contain quite some rust, but it is heavily contaminated with something else. Maybe carbon from the steel nails, maybe some other metal oxide, maybe even a mix of iron (II) and iron (III) hydroxide. The problem with this type of experiments is that the starting materials are so impure. An ordinary nail contains iron, but also a LOT of other metals, carbon, even small amounts of phosphorous, as phosphide. Also keep in mind that 15 V DC is way too much for electrolysis purposes. Try a 5 V DC power supply, with a decent current output. The current determines how much chemicals are formed, the voltage determines only which reactions will occur. A high overvoltage only results in heating up of the liquid. E.g. when the reaction requires 3 V, and 15 V is applied and the current is 1 A, then 3 W of power are used for the chemical reaction, and 12 W of power is consumed and heats up all things.

These pyramidal structures are able to concentrate mystical and cosmic kinds of energy. Also healing energies are concentrated inside pyramids. Crystals of all kinds of compounds can be charged inside a pyramid and the healing energies then are stored in the crystal. The crystal in turn has healing powers for a few weeks, when charged. Pyramids also create many negative ions, and these have a very good effect on your body. You feel well, when there is an abundance of negative ions in the air. Your spritiual life is enhanced and your mind opens up again by the good influence of all these negative ions. :rolleyes:

I don't see the special thing of this. It is always possible to create this effect by a combination of a DC-voltage source and an AC-current source, with the terminals of the voltage source connected to the terminals of the AC-current source. Between the two points, there will be a constant DC-voltage, and the current going through the wires will be alternating. Physically this means that the voltage source sometimes delivers energy, and sometimes it consumes energy. Nothing special though.

No, I did not say precisely this. I do not know the precise figures where you will get gaseous SO2. At a certain concentration of acid, you will get gaseous SO2, and the higher the concentration, the more gaseous SO2. With a 50/50 mixture of conc. H2SO4 and water, together with some heating, you will be capable of getting some SO2 gas.

If you mix up Na2S2O5 and H2O2 you don't get SO2, but NaHSO4 in solution. With excess Na2S2O5 you will get SO2 and indeed that has a pungent odour. The bubbles you saw, however, most likely are oxygen from decomposing H2O2. Budullewraag, SO2 is very soluble. It will be quite hard to get any SO2 from an aqueous solution. You just get the smell, but gas at reasonable purity requires more than just adding some bisulfite to an aqueous solution. SO2 is not as soluble as NH3 and HCl, but still is is soluble quite well. You can make gaseous SO2 by adding a bisulfite to a strong concentrated acid (preferrably H2SO4). From conc. HCl you can make it, but it requires heating to drive of the gas.

I would most like unlimited possibility of editing posts, UNTIL someone has added a more recent post in that thread, regardless of whether that is in response to your post or not (telling the difference would be impossible for a piece of software like that is driving SFN). That method assures thread continuity. I'm inclined to say, however, please think twice before you post. If you have to take back all kinds of things, while others have responded already to that, then it is more appropriate to add a new post.

One of the funny things I do is collecting the chemical elements. Most people stare at me when I tell about this, and even my wife thinks it is a strange thing to collect them . But it is fun to have them. And no, it is not secret. I agree with YT, that having secret hobbies for the people, nearest to you, would not be good at all. The elements I have already, I also put on the web: http://woelen.scheikunde.net/science/chem/compounds/index2.html Have fun with this strange hobby

Ecoli, I fully agree with you. This thread is going in a k3wlish direction. I've been thinking of removing this, but I'll leave this as a warning to all serious chemists: This is no fun, it is not original and does not add anything. THREAD CLOSED.

You don't need specifically mentos. Add a tablespoon full of sugar to fresh diet coke and you get the same result. You also get the same result when salt is added. Even when sand is added, you get a similar result but less strong. This is a two-sided mechanism. Part of the mechanism is just by adding much more surface, on which bubbles can form, hence the effect of sand. Another part of the effect is that dissolved sugar and dissolved salt makes the CO2 less soluble (it is already over-saturated) and drives it out of solution.

I fully agree with Atheist. Making artificial gravity of a reasonable level simply is impossible. The force of gravity is soooooo weak. On the other hand, it is the long distance force, which determines the global behaviour of the universe. But, here we are in speculation, so we may add some new "physics" . You could tell in your story that mankind has found a way to have mass in a very concentrated form in a hyper-plane, parallel and very close to, but not overlapping with our hyper-plane. In that parallel hyper plane there is a fairly small mass (still millions of tons, but nevertheless, much less than a planet, and achievable with sufficient economic effort) at very high concentration. When this mass is placed correctly in front of your mars-orbiter, then it gives reasonably uniform gravity (e.g. ranging from 0.3 to 0.5 G when going from the back to the front of that orbiter). In fact, what I'm saying here, is not all sheer nonsense, although it is for the most part. But there is a real theory, called "brane" theory. Some flavors are talking about super branes, containing huge masses, whose presence we can only notice by means of their gravitation. Whether this is real or not, remains an open question, it definitely is not established science.

Hey, nice to see that. I always thought it was As2S3. I've indeed done a google on arsenic sulfide and realgar in Google (without the quotes) and one of the pages is this: http://www.galleries.com/minerals/sulfides/realgar/realgar.htm It confirms what you say, it is As4S4, which of course has empiric formula AsS. Always nice to learn new things .

IIRC, Realgar is not AsS, but As2S3: http://webexhibits.org/pigments/indiv/technical/realgar.html The reaction will be As2S3 + 3Fe ---> 2As + 3FeS Now you could redo you molar computations again. If you really want to do this in practice (???), then be EXTREMELY careful. Arsenic is very very toxic and it is among the most toxic elements. It also is a carcinogen. Without proper lab stuff, this is insanely dangerous to perform.

I also am in the process of making high voltage generators, but these things also have a certain maximum current output. Usually these devices are specified as follows: - Output voltage at no load. - Voltage drop per mA of load. - Maximum mA, which may be drawn, before devices get overheated. A typical set of values may be: Output voltage: 30 kV Voltage drop per mA: 1500 V Maximum current: 3 mA This device then would be capable of delivering approximately 75 W of output power, which is quite a lot already for such a high voltage device. Some power supplies even allow much lower output currents, such as 1 mA, or even less. Of course, the numbers I gave are just hypothetical (but realistic for many devices). You will have to obtain the figures from your seller. Btw, what do you want to do with that 30 kV generator? Are you aware of the serious risks you run when playing around with these voltages. Even a 10 nF capacitor, which is not that large, will most likely kill you, when discharged through your body, when it is charged to 30 kV. So, be VERY careful.