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Posts posted by UC

  1. Not all compounds will be solid or crystals. In fact, all of mine are oils. Alternatively, you have a miniscule amount of solvent trapped in the material and so it doesn't crystalise



    There were compounds that I had to leave on a high vac line for 2 weeks before they would give up enough EtOAc to decide to crystallize.

  2. Depending on what you mean by water, heating the substance until the water evaporates, heating the substance in the absence of oxygen until all the oxygen leaves and adjusting for the produced gases, dunking it in a dissicating agent like concentrated sulfuric acid. Basically, take whatever you mean by water out, and measure what is left.


    Dunk it in sulfuric acid? :blink: That would certainly do something to it, but dessicate it properly is not one of them. Personally, I'd store the food item under a good vacuum over P2O5 until the weight stopped going down. Gentle warming may also help drive off the last of it without causing degradation.

  3. As defined by wikipedia, "Anime is commonly defined as animation originating in Japan." Anime generally utilizes a specific style of drawing, which is poked fun at in this bit of internet pop culture: http://www.homestarrunner.com/sbemail57.html. Many examples of actual anime cartoons with which to satisfy your curiosity are available online, through a simple google search. :P


    An amine refers to some derivative of ammonia and takes into account the entire structure. For example, it would be possible to call the amino acid glycine "carboxymethylamine." You treat the basic structure of the molecule as being an ammonia derivative and list the "added" carboxymethyl substituent.


    When speaking of a part of a molecule (referred to as a moiety), the term amino is used instead. Using the same example, you could call glycine aminoacetic acid. When using this naming convention, the base structure is the acetic acid skeleton and the amino group is the "added" part.


    This wikipedia excerpt should clear up up confusion: http://en.wikipedia.org/wiki/Functional_group#Groups_containing_nitrogen


    As for more examples, you could rename trimethylamine as N,N-dimethylaminomethane. Your confusion is largely just a nomenclature issue.

  4. If you read carefully, they used an HD camcorder. The iphone was merely there for the GPS tracking capability. Aditionally, I'm surprised that the handwarmers actually did anything given that they require oxygen to get hot and the atmosphere gets thin, quick. While the thinner atmosphere is more insulating,the 100mph winds certainly would help rob the container of it's warmth.

  5. Fish is fish. My only real objection to it initially was the chance for it to destroy native fish populations, should any escape into the wild. On the whole, that's my only real objection to GE. The females only and triploid information is new news to me and resolves the issue.


    You'll notice that nobody makes any fuss about GE e. coli used to manufacture human insulin for use by diabetics. Or if there was, I haven't heard it.

  6. Best bet would be to precipitate it as the calcium salt, isolate and wash, treat with aqueous sulfuric acid and filter the crude citric acid solution away from the solid calcium sulfate. Careful crystallization should then yield relatively pure citric acid.

  7. Here's an obscure one,


    -This compound displays extreme valency (coordination number is two digits)

    -The ligands in this compound are perhaps the stangest ever

    -The metal center often takes oxidation states of +2 or +4

    -The compound is binary in the sense that there is one metal center and one ligand type.

    -The ligands, in their atomic form have very high ionization energies.




    Could this be a solution of a group I metal in ammonia known as an electride salt?


    ex. [Na(NH3)x]+ e-



    You got it. Using ligands like 2,2,2-crypt, you can isolate an electride as a solid. If you evaporate the ammonia solution without a ligand, you just get sodium back.

  8. Well, as UC's puzzle has gone over 7 months without being solved I think I'll give a new puzzle to maybe revive this game.


    I can be bitter or I can be tasteless. It all depends on your genes.


    Easy. Phenylthiourea.


    Also, still looking for an answer for mine.

  9. http://en.wikipedia.org/wiki/Depletion_gilding


    Nitric acid isn't magical and able to penetrate solid materials, so you'll only remove what little is on the surface, building up an impenetrable layer of pure gold


    Have a look at this. By diluting the gold with silver (which is susceptible to nitric acid), you can penetrate the entire solid and leave behind only gold and other metals that do not dissolve in nitric acid:

    Plenty of reading material here: http://goldrefiningforum.com/

  10. Is it unusually light or unusually heavy for it's size? Galena (PbS) looks an awful lot like silicon except for it's density. Silicon is oddly lightweight.


    Value depends entirely on purity and since we humans make vast quantities of ultrapure (99.9999+%) silicon for electronics it's value won't be terribly high in any case. More likely it is of lower purity from an earlier stage of refinement- at worst about 98%. You wouldn't be able to get more than a few dollars for it without knowing and even the ultrapure material wouldn't get you much more.


    If it's galena, it won't be too valuable anyway as it is a fairly common mineral.

  11. Clearly alchemy is the answer.


    Into a large earthenware vessel, place a synthetic plastic card, known as a credit card. Take care in writing down the numbers engraved upon it.


    Upon the device known as a computer, find a website that sells the caustic that you seek- perhaps for making soap or bio-diesel.


    Enter unto the named boxes the numbers of the plastic card, checking carefully. If thou shalt fail in this step, the transformation shall not be completed. Enter also your name and address as required and press upon the button marked "order."


    Allow the card to remain in the earthenware vessel for 3-10 days until the messenger of the winds delivers unto you a brown vessel containing the caustic that you desired.

  12. H2O2 is a relatively poor antibacterial at low concentrations, IIRC. H2O2 injection combined with ozonolysis is much more effective IIRC as it generates free hydroxyl radicals. This however is probably quite a bit pricier than the old standby chlorine (or chloramine treatment)

  13. That specific grignard cannot be prepared. The reaction instead proceeds by the formation of ethylene and 1 equivalent of magnesium bromide. In fact 1,2-dibromoethane is a common initiator for sluggish grignards because the product removes itself from the reaction mix as visible bubbles.

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