woelen

I just installed Ubuntu 6.10 on my new PC with an ASUS P5L-MX motherboard, using the Intel 945 chipset and Attansic L1 gigabit ethernet adapter. The processor is an Intel Core 2 Duo E6300. This PC also has an nVidia video adapter, a 7300LE with 128 MByte of RAM (no, I'm not a gamer, so I keep my video adapter lean and mean , and especially, I keep it cheap). I have everything working fine, except the X environment. I downloaded the latest nVidia Linux driver from the nVidia website and installed this, using the run script. It installed, but it gave a warning that it cannot determine the location of my X.org installation. It installs anyway, but the warning makes me suspicious. After that, when I start X, everything seems to work fine. It picks up the new nVidia driver, perfectly detects my video adapter (it reports the correct type), and it also runs some 3D/OpenGL applications without any problems. I'm running this beast at 1400x1050 resolution at 85 Hz refresh rate. So far so good. Then, I rebooted my machine and to my horror it does not start X. A somewhat cryptic/scrambled screen appears (in crappy text mode) and I get the following message: X Window System Version 7.1.1 Release Date: 12 May 2006 X Protocol Version 11, Revision 0, Release 7.1.1 Build Operating System: Linux 2.6.15.7 i686 Current Operating System: Linux moller36 2.6.17-10-generic #2 SMP Fri Oct 13 18:45:35 UTC 2006 i686 Build Date: 07 July 2006 Before reporting problems, check http://wiki.x.org to make sure that you have the latest version. Module Loader present Markers: (--) probed, (**) from config file, (==) default setting, (++) from command line, (!!) notice, (II) informational, (WW) warning, (EE) error, (NI) not implemented, (??) unknown. (==) Log file: "/var/log/Xorg.0.log", Time: Sun Dec 3 21:33:05 2006 (==) Using config file: "/etc/X11/xorg.conf" Error: API mismatch: the NVIDIA kernel module has the version 1.0-7184, but this X module has the version 1.0-9629. Please make sure that the kernel module and all NVIDIA driver components have the same version. (EE) NVIDIA(0): Failed to initialize the NVIDIA kernel module! Please ensure (EE) NVIDIA(0): that there is a supported NVIDIA GPU in this system, and (EE) NVIDIA(0): that the NVIDIA device files have been created properly. (EE) NVIDIA(0): Please consult the NVIDIA README for details. (EE) NVIDIA(0): *** Aborting *** (EE) Screen(s) found, but none have a usable configuration. Fatal server error: no screens found I did a reinstall of the nVidia driver (without overwriting the existing xorg.conf file) and when I do that, everything works fine again, I can start X again. But when I reboot the system, I again have to install the nVidia driver . The system now is in a state that all works fine, and even the video adapter works fine, but I have to reinstall the video driver every time I start the system, before I can actually use my X environment . When I go back to the "nv" driver, instead of the "nvidia" driver, then X always works (also in 1400x1050 @ 85 Hz), but with that driver I do not have hardware accelerated OpenGL support. Are there any people over here, with experience with this? I tried several things, like downloading and reinstalling the Ubuntu Nvidia X.org package again, but no succes.

No need to worry about your health with this one-time exposure, but next time please be more careful. A very good precaution for dust is to use a towel and bind it around your head (mouth and nose). Not really pleasant, but it works for dust (not for gases). Getting rid of the chromate waste and contaminated material is not that hard. Put it in a bucket (yes, all, the complete cardboard), add water and add some hydrochloric acid and some sulfite. The hexavalent chromium is reduced to trivalent chromium. If it is just a small amount (not more than several grams), then you can flush it down the drain as trivalent chromium. Trivalent chromium hardly is toxic.

The best yellow is from cerium metal in the +4 oxidation state. Very pure and intense almost monochromatic yellow. Another good yellow is made by vanadium in the +5 oxidation state at suitably adjusted pH. But this one is very sensitive on pH. Have a look on my website, I did a lot of experimenting with this. Yet another good one may be the tetrachloroferrate (III) complex, made by dissolving any iron (III) salt and adding excess chloride and some acid. Dissolving such a salt in HCl of medium concentration also is OK. http://woelen.scheikunde.net/science/chem/solutions/ce.html http://woelen.scheikunde.net/science/chem/solutions/v.html http://woelen.scheikunde.net/science/chem/solutions/fe.html

And we have the warmest fall ever since temperatures are measured. Average temperature (over days and night) was 13.6 C over the months of September, October and November . Last weekend we had 17 C, which never happened before in the last week of November, as long as measurements are done over here (for appr. 300 years). Still it is quite warm for the time of year, with temperatures between 10 C and 15 C, while normally start of December has 6 or 7 C.

For me, the only bromates, which I can make easily are potassium bromate, barium bromate, and with some difficulty, strontium bromate. If I had cesium salts and rubidium salts, then I also could make CsBrO3 and RbCsO3 (and yes, I hope to receive 100 grams of CsBr soon). The reason why these bromates can be made easily is their large difference in solubility at high temperature and low temperature. This makes separation of the bromates very easy, in fact, the K-, Ba-, Cs- and Rb- bromates are among the easiest to separate chems, due to their unique solubility as function of temperature. Unfortunately most other bromates are very soluble and there is no easy way to separate them from impurities. Silver bromate also can easily be made. It is insoluble and forms a precipitate, when e.g. solutions of AgNO3 and KBrO3 are mixed. AgBrO3, however, is more dangerous than the other bromates. A mix of AgBrO3 and Mg powder can be ignited (explosively) by adding a drop of water to the fine mix. I intend to do some experiments with Ag(NH3)2BrO3 as well, that is a compound, which has oxidizer and reductor in perfect ratio in its own molecule: Ag(NH3)2BrO3 --> AgBr + N2 + 3H2O Is this true? I always thought that Sr-salts hardly are toxic, provided the anion is not toxic. Of course, Sr(BrO3)2 is quite toxic, but this is because of the bromate, not because of the Sr. Iodates are not that interesting in pyro-applications. They are less reactive than nitrates. With sulphur you obtain little more than smouldering, with red P, they give a nice burning mix, something like a coarse mix of KNO3, S and C. KNO3 mixed with red P can lead to flash-like behavior. Iodates do form an interesting group of compounds in aqueous chemistry. They form amazing precipitates and complexes and also can be used for interesting clock-reactions and oscillating reactions.

I have done the phosphorus/bromate reaction (with 20 mg or so) and yes, this explodes. It is not a real detonation, but the burn rate is so high, that even the unconfined powder at 20 mg quantity gives a fairly loud bang. Not useful for making good colors.

Unfortunately this will not work. It will burn, but the carbon introduces a strong yellow/orange glow to the mix and the total color will be a much paler green.

The following is a really nice experiment with a deep green, which I seldom see in fireworks displays. http://woelen.scheikunde.net/science/chem/exps/barium_bromate/index.html You really should see the fire itself. The camera images capture some of the green, but in reality it is much brighter and more saturated. The camera has a difficult job, capturing the beautiful color, due to overexposure (and I cannot adjust its aperture in video-mode ). But anyway, if you have the chems, then you should definitely try this yourself. You can use crude potassium bromate and cheap potteries barium carbonate for making the barium bromate, as described in the thread on making potassium bromate. No need to use nicely refined material. Only the presence of sodium ions should be avoided, those will kill the nice green color.

This also rules out vanadium. Vanadium in its minerals has oxidation state +4, and that would give blue ions (vanadyl). For the yellow color I only can think of iron impurity, or organic material, which was trapped into the impure mineral. Try adding a mix of red and yellow prussiate of potash. Add just a few tiny crystals of both prussiates to the acid mix and shake to dissolve. If you obtain a blue color at once, then there is iron impurity. You do not need to fear possible formation of HCN, if you only add a few mm³ of solid.

If you added the emeralds to the colorless HCl/HNO3 mix and then it once turns golden yellow, then indeed it is not due to formation of ONCl. Formation of ONCl takes some time, even for the hot liquid it still takes a few minutes. If the color appeared at once, then it must be some impurity from the emeralds. Try to dissolve one in conc. HCl only. Doesn't it give the same effect? The trouble with such things is that the composition of the used materials is so very uncertain. They could contain all kinds of metals. Vanadium can lead to yellow colors for the pervanadyl cation, which certainly is formed under the strongly oxidizing conditions of HCl/HNO3 mix. Iron (III) also leads to yellow colors, due to formation of the tetrachloroferrate (III) complex, but that also happens in plain HCl, without HNO3.

Aqua regia becomes yellow/orange after a day of standing, even without anything added to it. When it is heated, this reaction goes much faster and may take only minutes or tens of minutes. HNO3 + 3HCl ---> Cl2 + ONCl + 2H2O The Cl2 is pale green, the ONCl is bright orange, the mix has a golden yellow color. Both gases remain dissolved in solution. Just as a test, take 0.5 ml of conc. HNO3, take 1.5 ml of conc. HCl, and mix. You'll obtain a colorless liquid. Next, heat this mix, without adding anything. Within 5 minutes or so, you will see the yellow/golden color, and the same color of gas mixture above the liquid. ======================================================================= if you want to see the pure color of ONCl, then add a spatula of NaNO2 (nitrite, not nitrate) to conc. HCl. The liquid will turn beautifully orange at once: First, the nitrite reacts with the acid in solution: NaNO2 + HCl --> NaCl + HNO2 (the white solid, which does not dissolve is plain salt) Next, nitrosyl chloride is formed: HNO2 + HCl ---> ONCl + H2O Nitrosyl chloride has a beautiful orange color.

So, it seems that the bromate BZ reaction also runs without the manganese. That is an interesting observation. Could the ferroin affect the reaction. It is an indicator, but of course, it does some redox, so I can imagine that this now is the driving force for the reaction and that, due to the low concentration, it becomes very sensitive to small variations in concentrations of the other reagents. Just my idea about this. I will try the BZ reaction also without manganese sulfate. I have no ferroin, but I might be able to see oscillation patterns in the bubbling of the mix. Another seemingly oscillating reaction is mixing HCl 30% with H2O2 30%. When you do this, then it has periods of vigorous bubbling and periods of low activity. During the periods of low activity, the liquid seems to turns deeper green. It is somewhat fuzzy, but it looks like an oscillating reaction. I know that HCl and H2O2 can give Cl2 and H2O, and at the same time, Cl2 and H2O2 can give H2O, HCl and O2.

Methylfluoride is quite inert, as many of the fluorocarbon compounds. This is what made the freons so popular. Their inertness makes them non-toxic. But unfortunately, at high altitude with lots of UV-light they cause catalytic decomposition of ozone, by means of a radical/recombination mechanism.

Question (A). Some elements have well-known oxidation numbers in their compounds. Oxygen usually has oxidation number -2 in its compounds, except for peroxides and superoxides. Fluorine ALWAYS has oxidation number -1, chlorine always has oxidation state -1, except in some chlorine/oxygen-compounds and chlorine/fluorine-compounds. Hydrogen almost always has oxidation number +1, except in some metallic hydrides. In their elemental form, all elements have oxidation state 0. Now we are going to solving (A). The first compound is (NH4)2HPO4. This is an ionic compound, consisting of ions NH4(+) and HPO4(2-). I do the trick for NH4(+), then you should be able to do for HPO4(2-). For NH4(+), total charge is +1. Now we have ox(N) + 4*ox(H) = +1, here ox(X) is the oxidation number of element X. ox(H) = +1 ===> ox(N) = -3. Write down the equation for ox(P), ox(O), ox(H) and determine ox(P). For compound (b) it is really simply: ox© + ox(O) = 0 (we have a molecule, not an ion, so total charge equals 0). For compound © it is not much more difficult than for compound (b) ==================================================================== Now for question (B). Again, using the well-known values for O, H, etc. determine the ox(X) for the element N in equation (a), for the element Cr in equation (2) and for element Cu in equation (3). Only for the reactions, where oxidation states are different, one has a redox reaction. E.g. for HCl + NaOH --> H2O + NaCl, you see that it is not a redox reaction. Oxidation states are the same left and right of the arrow. E.g. for 2HCl + O3 ---> H2O + Cl2 + O2 one has a redox reaction. Chlorine is going from -1 to 0 and one of the oxygen atoms is going from 0 to -2. Keep in mind, some compounds can at the same time be oxidizer and reductor. This may seem very surprising, but it is not uncommon.

Ryan, thanks for that synth you mention with red P, I2 and CH3OH. I am going to try that reaction on a small scale. I have all three chems. I did not know of that. Yes, it is quite unstable. That is why it is such a good methylating agent. It can easily split off a CH3-group.

One synthetic route is the use of tertiary ammines (in your case N(CH3)3), which are alkylated with alkyl iodide. For you the following would do. N(CH3)3 + CH3I ---> [N(CH3)4](+) + I(-) Unfortunately I am afraid that the reagents for this are equally difficult for you to obtain. What you could try is obtaining triethylamine. That is a compound which is somewhat easier to obtain. I have some of that compound. It is a nasty compound though, which is liquid, volatile and very irritating. I have no clue where to obtain CH3I. The latter is an extreme methylating agent and as such is extremely dangerous. It is very potent, it methylates your DNA, and that is not good at all! It is funny to see that a fairly benign compound as a quaternary ammonium salt can only be prepared through the use of really nasty reagents. I myself would not try to do this in a home lab, to my opinion the reagents are too toxic.

I know from recent experience that Pt is wetted by molten tin and also dissolves in it. So, I can perfectly imagine that gold dissolves in tin.

Such ionic compounds, as you mention here, are not special. There really is a big difference between such salts and real organometallic compounds. So, for me a compound like Ni(CH3COO)2 is not special, but a compound like Ni(C5H5)2 is special. A good criterion for a compound being a real organometal compound is the presence of direct metal-C bonds. The latter type of compounds is quite new and extensive research on this kind of compounds only started in its full strength in the 1960's. Of course, some compounds of this type were known earlier,e.g. Ni(CO)4, but real understanding of this also was after WW II. You now see a trend, where the term 'organic chemistry' is abandoned again. Nowadays there is the trend of simply speaking of 'carbon chemistry'. The border between classic organic and inorganic is not a sharp border, there is a large fuzzy area.

I do not know the term, but I think it describes the fact that in most real chemical compounds the bonds are not purely ionic, nor purely covalent. Many many compounds have inbetween bonds. Purely ionic compounds have separate ions in a crystal lattice, with totally separated charges. Examples are NaCl and CsF, they consist of Na(+) ions and Cl(-) ions, or Cs(+) ions and F(-) ions. Purely covalent compouds are CH4 and CO2. There are, however many inbetween compounds. A compound like CuCl2 is often called a salt, consisting of Cu(2+) ions and Cl(-) ions, but in reality it better can be described as a structure with Cu(2d+) and Cl(d-) charge, with d being a number between 0 and 1. The Cu-atoms are loosely bonded to the Cl-atoms, making it somewhat covalent, and at the same time, charge is separated, negative charge being withdrawn towards the chlorine atoms, but it is not fully withdrawn. So, CuCl2 can best be regarded as an intermediate compound, with covalent properties, and somewhat ionic properties. Many salts are of this type, espcially the metal halides, but also acetates and in general salts of weak acids.

Everything I write below, I write as a private member and not as staff opinion. I agree with raivo, and I also want to add to raivo's words, that unfortunately a certain amount of arrogance is grown in the community over here at SFN. I have seen it very strongly in the religion forums, but sometimes it also pops up at other places. Some people give the impression they are the enlightened ones, and every question can be answered with science. The latter simply is not true, but unfortunately a group of people tells so, and if you are expressing your doubts on that and you express your doubt on the far-reaching implications of "established" theories, then they make a mockery of you. For this reason, I also have become much less active over here. I do basic mod tasks (such as removing obvious spam, advertising and so on) and do post in math and chem, but that's all. I am posting on the theologyforum occasionally, but not very frequently, but over there, I notice a similar attitude from some members. If SFN wants to continue to be a lively and active community, then the narcissistic/overweening attitude of some members must be reduced. Now SFN more and more seems to become a small community in its own, with a select group of people, and all other members are outside of this community. In other words, we have a community in a community.

I have made some KBrO3 from KBr and this synth was quite succesful. I used this for my oscillating reaction experiment, and also for some other energetic materials experiments. The synth is described here: http://woelen.scheikunde.net/science/chem/exps/KBrO3_synth/index.html Have fun, but be careful. KBrO3 is a possible human carcinogen. It also can react very energetically with some reductors.

Unfortunately, oxalic acid doesn't work. If you look at the reaction mechanism for oscillating reactions, then you that that you need a specific pathway for the oxidation of the organic compound. Oxalic acid is oxidized straight away, you simply get CO2 and bromide (or bromine if KBrO3 is in excess) and that's all. I also tried ascorbic acid, and that gives a similar non-interesting result. Up to now, I only found malonic acid and citric acid as useful reagents for the oscillating reaction, and citric acid only does so in a limited way. You get loads of turbid crap in the liquid and it makes the reaction much less attractive.

I finally could do an oscillating reaction at home. It is really cool to see this happen. The chems, needed for this experiment are quite easy to get your hands on, or you simply make them. Most notably the needed KBrO3, I made this myself, another page on that will follow soon, a solution, containing Mn(2+) ions also is not that hard to make if you don't have manganese (II) salts. http://woelen.scheikunde.net/science/chem/exps/oscillating/index.html The only chemical, which is harder to obtain and quite expensive is malonic acid, HOOC-CH2-COOH. Citric acid can be substituted for this, but the effect by far is not so nice with citric acid.

There is nothing to believe on carbon dating. It is just a method, used for estimating the age of a certain (organic) object. Nothing more and nothing less. This kind of issues goes much deeper and has a religious nature. For that kind of discussion, I, however, want to refer you to our "sister"-forum http://www.theologyforums.net and please do not start that kind of discussion over here. This is a math forum and not a religion forum.

I would call this compound trifluoro hydroxy methane. Maybe the name trifluoromethanol can be used as well.