Jump to content


Senior Members
  • Posts

  • Joined

  • Last visited

Posts posted by UC

  1. If you follow the link in the lithium article to the Sir Humphrey Davy article, you will find that Lithium oxide is almost surely a typo and should be lithium hydroxide. Electrolysis of molten lithium hydroxide generates the molten metal at the cathode

  2. Yes, all of those compounds are salts. A salt, in the chemistry sense, is an ionic compound that can be formed by the neutralization of an acid by a base. Some of these are not soluble in water, but those that are dissacociate into ions in solution. They are also known as electrolytes. The common use of salt is sodium chloride which fits this description.


    Sodium tetraborate (borax) and various sodium acid salts of ethylenediaminetetraacetic acid are also used for laundry, but the chemistry sense of "salts" covers an essentially infinite number of compounds.

  3. I realize this. It does get rather sketchy in places, but you can't argue atomic number or the s, p, d, and f blocks as a general means of organization. The properties of the elements arise at least partly, if not mostly from their electron configurations, and as a result, are just as inconsistent in places as the electron configurations.

  4. No. The 12 volt Lithium battery you refer to is probably actually a Li ion battery. These batteries IIRC, rely on cobalt redox to generate current and use a lithium salt as a carrier. Smaller batteries that are not meant to be rechargable are that way for a reason. Reversing current through them is either highly inefficient at regenerating the compounds that give you the current, or may lead to gas evolution and rupturing the battery, perhaps with some violence. AA type lithium batteries actually use lithium metal and are not rechargable.

  5. What size coil are you looking to make and out of what material? As alien said, a drill and some rod stock (metal is much better than wood. in some cases wood will be useless) is your friend for narrow coils. For larger ones, I recommend a bit of pipe locked into a vice and some hand power. I make coils all the time, then cut them up one side to make rings for chainmaille armor and jewelry. :)

  6. Spiffy

    Merged post follows:

    Consecutive posts merged

    and at the same time, delicious.


    Very nice! It's a solution for those who are incapable of using the edit button. Speaking of which, is therea time limit for editing one's posts? It appears that there is, but how long is it before they lock?

    Merged post follows:

    Consecutive posts merged

    Also, I love waffles :D

  7. Ibeamer, you might also want to note that the reaction gets hot, extremely hot if you use strong lye and lots of aluminum foil. That is, however, a decent way to get hydrogen.


    DIY Electrophilic aromatic substitution:



    -Test tube or similar small, clear container


    -Sodium bromide (NaBr. This is available as a bromine reserve starter for hot tubs/ spas)

    -An acid (HCl, H2SO4, H3PO4, or any reasonable strength acid is acceptable. Sodium bisulfate is marginally acceptable, but stronger acids produce better results)

    -Hydrogen peroxide solution (3% is available in most food stores as an antiseptic. Other concentrations are available if you know where to look)

    -Chloraseptic spray (I'm not sure if this is available outside of the US. Make sure the bottle says it has phenol in it)


    A tiny spatula of NaBr is placed in a test tube or any clear container that you can observe the reaction in. Add a few drops of hydrogen peroxide solution. I used 6.5%, but 3% will work as well. Just use a little bit more if you're using 3%. The solution is acidified. I used a few drops of concentrated HCl, which produced a red-brown solution of bromine in water. Even sodium bisulfate (with a little water) will work, but the mixture appears yellow because the concentration of bromine is lower. The mixture is diluted a bit with water, so there is some room to see the reaction above any undissolved solids, and a few drops of chloraseptic spray is added. The chloraseptic spray is a source of phenol, a good example of an activated aromatic ring. The color of the solution fades as the bromine reacts, and a white precipitate forms. This precipitate is 2,4,6-tribromophenol, which has an intense antiseptic smell. With the red-brown solution, the drops of chloraseptic formed a thick white layer upon hitting the bromine water. With the dilute, yellow solution, there was a bit of delay before much precipitate formed, which clouded the solution, instead of forming a compact glob. The quantities used here are extremely small, and the few milliliters of waste (containing at most a few milligrams of tribromophenol) can be disposed of in the trash.


    Happy experimenting :cool:

  8. I yell at the screen sometimes when I see stupidity...like the mythbusters episode where they put an entire pair of blue jeans in a huge bomex (!!! can't they afford pyrex or kimax) beaker full of H2SO4 and HNO3 (They appeared to be reagent grade which further confuses me as to why they were using cheap bomex stuff, which is thin walled and often has bubbles in it). I haven't seen the episode in a while, but I don't think there was an ice bath, so the reaction ran away and started spewing NO2 fumes.


    Also on the hindenberg-thermite episode, they failed to test all combinations of experimental conditions. It was really glaring to me, but probably not to most people.


    At any rate, the show is a lot better than brainiac, despite a lot of little mistakes and a few big ones.

  9. I'd reserve a retort for high boiling materials that demand strong heating (and will condense easily with only air cooling), but that aside, cooling the neck in some way will give you your desired effect. You could run ice water over it, but you'd need to attach some sort of something to the end of the neck to keep the water from getting in your distillate. A bead of caulk intended for bathroom work would be a good waterproof "glue" to attach such a barrier

  10. Try heating some concentrated NaOH or KOH solution up in the crucible, and keep the alumina submerged. This won't attack the iron, but will dissolve the alumina as sodium (or potassium) aluminate. You might try molten NaOH if hot concentrated aqueous solution won't get rid of it.


    You may get a thin skin of rust where the hydroxide is, but it buffs out very easily.

  11. Look up solubility curves of NaCl and KCl. You'll find that NaCl has very little swing in solubility from 100C to 0C while KCl is quite a bit more soluble at 100C than 0C. So yes, dissolving in boiling water, filtering (if there is other gunk in the mix), and cooling will give a crop of crystals rich in KCl. It is possible that there will be no NaCl, but that depends largely on how much of each is in the original sample.

  12. This depends entirely on if you want to operate in a system of pure mathematics or in the real world. In a system of pure mathematics, then yes. The contact between the two would be a single point. If you want to operate in the real world, but want to use two perfect spheres of an infinitely incompressible material (not quite the real world), you still have to contend with the fact that atoms aren't quite as definite as mathematical objects. The aren't hard, sharply defined, closely packed spheres.

  13. Use a small amount of acetone in a cup. Adding the peanuts releases their blowing agent and reduces them to styrene (I assume) scented goo. There is no reaction, just a weak solubility that allows the filler gas to escape. Polystyrene is used to make all sorts of things and most end up in the trash, so at least it'll be low-volume trash.

  14. First of all, proper sentence structure and capitalization will get you far in life. A better question would have been, "Is it possible to make KNO3 from urea or NH4NO3, and how would I go about doing this?" People tend to assume you're a 14 year old kid who wants to make big explosions in your backyard if you ask about things like KNO3 the way you did.


    Urea could be made into nitrates by using it as food for nitrobacter bacteria or by decomposing it into ammonia and leading it through heated catalyst tubes with just the right proportion of oxygen to convert it to nitrogen oxides, which are absorbed in water, forming nitric acid, and then neutralized to nitrates. Then again, I dont know of anyone who can do that on a hobby scale.


    I certainly hope you don't have NH4O4. I've never even heard of such a compound. It's probably really dangerous. :rolleyes:


    No, what you have is NH4NO3. ammonium nitrate. Boil with a stoichiometric amount of potassium carbonate or potassium hydroxide until ammonia stops coming off, concentrate and chill the solution, disturbing it as little as possible. Long, needle-like crystals of KNO3 deposit, which can be filtered from the solution, rinsed with ice cold water, and dried. If you shake it up or move the beaker too much, you get lots of extremely fine crystals which trap the solution between them, dissolve rapidly when you try to wash them, and take eternity to dry out.


    Why do you need KNO3 so urgently? If this has anything at all to do with the anarchist's cookbook, please delete or throw out your copy right now. It is garbage and you will hurt yourself. Pick up an inorganic chemistry textbook at the library. Learn it. Bonding, Ions, stoichiometry, double displacement/metathesis reactions, redox chemistry (this one is absolutely vital but you won't understand without the other material). The only way you will be able to make any kind of pyrotechnics properly and responsibly is if you understand what exactly is happening.


    I'm sorry if I've gone on a tirade there for no reason, since I have no idea why you want potassium nitrate anyway. Have fun making it if you do. Cheers :)

  15. Hey there's plenty of stuff you can do with a furnace that can melt steel. Do your own alloying, melt down aluminum cans into ingots. smelt your own metals. If you have a taste for the dangerous and can afford a quartz reaction vessel, it can probably be used to make sulfur trioxide en-masse from sodium bisulfate. If you don't know what to do with this material neat, you can always dissolve it in sulfuric acid and make your own oleum or dilute that and make clean, reagent grade sulfuric acid without spending a fortune. That is also discussed in the forum I linked. Cheers!



  16. You're better off using the hydroxide. It has a lower melting point and no several hundred degree chlorine gas to deal with. Thermal reduction of carbonate with carbon sounds sketchy. I suspect you won't make anything, but If it does work, the sodium will be vapor at those temperatures. Carbon is not a magic bullet for reduction. If you have a piece of sodium, please sink it in some dry mineral oil before you try to melt it. Doing it outside without inert atmosphere will give you a UV-rich, blindingly white fireball, which is cool, but not what you want, I suspect


    On molten state electrochemical approaches:



    Actual success with a castner cell:


  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.