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John Cuthber

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Everything posted by John Cuthber

  1. NH3OH? Not seen that one before. Essentially the products of dissolving NH4Cl in water are very dull. No reaction takes place except the hydration of the ions.
  2. An interesting and potentially useful thread but I think it's aimed at the wrong disease. HIV is causing and will continue to cause massive harm in the world but, from the point of view of anyone reading this thread, it's almost completely avoidable. Wouldn't it be more sensible to apply our minds to the problem of malaria? With global warming clearly happening (whatever the cause), many areas that were previously almost unaffected will be at risk. Currently both diseases cause something like 2 or 3 million deaths a year so perhaps we should worry about both.
  3. My word, what a lot of tosh. For a a start, H2O2 is more stable in weakly acid solution than in alkaline conditions so the whole idea is base over apex. A more sensible reason for the foaming is the presence of catalase in the blood. It's there specifically to destroy peroxides because they are toxic. Blood is, incidentally, faintly alkaline, but not strongly enough to markedly raise the decomposition rate of peroxide. Why persist in this weird idea about H potential?
  4. Well The answer to the first bit is easy. " does a line between 2 atoms mean it is chemically bonded?" Yes. " What signifies what type of bond it is? Are the covalent or ionic bonds?" Almost all the bonds in the molecules you see in biology are covalent. Sometimes there are hydrogen bonds indicated, but that's usually stated as such. The second bit is more difficult because I'm afraid I don't know what you mean. Please could you post a link to an example.
  5. Ozone levels near the sea are generally low. The idea that there's much ozone there is a myth. On the other hand I have heard that ozone was used as an air steriliser come sanitiser on the London Underground. As long as the levels are low the ozone won't do much harm. To get rid of the smell of a couple of long-dead pigs isn't something you could do with levels of ozone that wouldn't damage people (or at least not in any reasonable time sacle)
  6. OK first point. "you get the poster angry and they reply quicker. It was my method to get him to support his answer." He didn't ; your idea failed. Secondly. "but openly refuting what someone says isn't." You need to look up what refuting means. If you had genuinely provided evidence refuting his point then this would be fair comment. Simply saying he's wrong isn't the same thing, and it makes you sound like a 2 year old. Thirdly "However, I will want you to support what you tell me." Surely you are joking? You didn't offer any suport for your wrong headed idea. On the other hand you were prepared to accept the word of your prof. Perhaps you should learn that some of the people how post here are respected scientists. At the very least you ought to accept that, given his post count, ecoli is quite likely to be right. People don't generally get by here for that long unless they know what they are on about.
  7. OK if you want the science side of things; it's poor science to pontificate about things when you are an ignoramus. And, BTW, as for "Who cares that much about politeness? ", I think you will find that many of us do. Have you read this? http://www.scienceforums.net/forum/announcement.php?f=51&a=14
  8. Actually I'm not sure about CuFeS2. I think it's a single (though probably non stoichiometric) compound. http://en.wikipedia.org/wiki/Chalcopyrite Iron pyrites is FeS2. I think you could get substitution of Fe(II) by Cu(II). And I'm not offering to give a balanced equation for oxidation of that in air. Some H2S will be lost, some SO2 probably would be too. I'm not ruling out S8 as a possible product.....
  9. Just a thought. Is having drugs tailored to racial characteristics morally different from having drugs tailored to the sexes? I grant that it's generally more difficult to establish the racial traits than sex, but if that distinction can be made then what's the problem?
  10. A practical relalisation of putting it an a spring and measurng the peiod of oscillation is given here. http://en.wikipedia.org/wiki/Quartz_crystal_microbalance These things are used in vacuo as often as not.
  11. "I talked to my professor " It might have been more helpful and more polite to do that before posting.
  12. Actually you could get repulsion if you were to use an alternating magnetic field. This would work for any conductive bullet. On the other hand the electromagetic coils and power supply would weigh so much that you would be better off hiding behind them.
  13. "CuFeS2 is a single compound a mixture of compounds." Pardon?
  14. Well, shadowact, you are half right. It is 10 vol, not 5. On the other hand have a look at eqn 5 in this http://www.ic.sunysb.edu/Class/che133/susb/susb035.pdf
  15. "it's an chromatography assay." Oh no it isn't.
  16. OK, 3% peroxide will generate about 5 times it's own volume of oxygen. That's plenty to see the reaction, even if it's a bit low for making the bulk gas. H2O2 is relatively stable in acid conditions so adding an acid won't do much to decompose it. Adding the peroxide solution to dried yeast will decompose it nicely. Adding it to potassium permanganate will do even better- you get twice as much oxygen gas for the same amount of peroxide. On the other hand, permanganates stain everything in sight and are relatively toxic. I'm not sure what Mr Sandman feels he has added to the thread.
  17. I think FeCuSO4 should be written as (Cu/Fe)SO4 ie a mixed Fe and Cu sulphate (both as 2+ ions). Made by oxidation of the similar mixed sulphide/ pyrites mineral. The most likely oxidising agent is a mixture of water and air. If I'm right about that then it's soluble in water. The sulphide isn't.
  18. Since the noble gases are perfectly able to form plasmas where they have less than the full complement of electrons that's not a reason for mentioning them here. On the other hand, they are as good an example of a plasma as any. "Does a gas become a plasma when an electrical current passes through it, or at a certain temperature? Both?" Well, both is probably the best answer. Any atom or molecule on its own in a gas might get ionised. It might be hit by another atom (or whatever) and lose an electron . It might get pulled apart by an electric field or it might get hit by radiation of some sort. In a flame some of the molecules are hot enough to be moving fast enough to chip electrons of molecules and atoms. Some of the maolecules in a candle flame are ionised so it is a plasma. On the other hand, most of the molecules are neutral, only a small frraction are ionised. A candle flame is, therefore, a weak plasma. In a neon lamp the initial ionisation can be caused by the electric field but it's sometimes caused by radiation. The normal background levels of radiation can sometimes do this. Whatever produces the first pair of charged particles- say an electron and a Ne+ ion, they are atracted to the electrodes in the lamp. The elelctron is drawn to the + electrode and the Ne+ ion to the - electrode. Usually, before they get to their destinations they plough into another atom of neon. If they are going fast enough they ionise this atom too. In this way you can readily ionise a lot of gas. After a while many of the atoms are ionised. Some of the ions get hit again and lose a second electron to give Ne++. Of course this is rarer than hitting an unionised atom so there are usually fewer Ne++ ions than Ne+ ions. Higher charged ions are also made, but these are rarer still. The atoms that get hit might not get ionised. They may just have the electrons knocked away from the nucleus into a higher orbital. When these electrons fall back they give out the excess energy as light. PPS you won't get Mg from Li that way, but you might get Be.
  19. Pioneer is talking nonsense saying "Gold has an almost a perfect balance between the proton's in the nucleus and the electrons in its orbitals, which makes gold very inert.". Every metal has exactly the same number of electrons round the nucleus as protons in it. Sodium for example has 11 protons and 11 electrons. It is hardly inert. I think the essence of the reason is very simple. Gold is soft so it can be peeled off easily and it's generally pretty inert so it doesn't bond to substrates like glass. IIRC silicone grease is also used for this sort of thing but it clearly depends on the context. What are you hoping to release from what?
  20. Everything is toxic, to some extent. Copper and iron compounds are unusual in that they are needed by the body in relatively large amounts ( a few grams of iron and a few centigrams of copper) but are quite toxic when present in excess. Anyway, you are right in thinking that the oxidation state of the copper and iron son't change, but look at the sulphur. As for the effect on the environment it will depend greatly on how the stuff is worked with. Obviously, if it's transported carefully in sealed trucks then there's less of a problem than if it's left to blow about the place.
  21. Perhaps we have different versions of the idea of floating, but "tied up with a bit of string" doesn't feature in mine.
  22. As far as I know lactose is only produced by female mammals to feed their young. That is its function. Bowels generally work just fine without it (except in the case of young mammals). Also lactose intolerance is rare where I live (in the UK) so I stand by my assertion.
  23. "Teachers have a professional responsibility to be respectful of their students beliefs. But firing over that is just lame." Imagine this scenario. OK Johnny, I think that 2+2 is 4 but if you want to believe that it's 5 that's just fine. I may have missed something but I thought the whole point of having a teacher was that the teacher knows stuff which is factually correct and teaches it to the kids.
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