Recent content by chem_tr

  1. chem_tr

    Decrasing solubility of quaternary ammonium compound in water

    Thank you for your interest.. I do not have the facility to freeze-dry the compound, so I think I will use high vacuum and distill the water to attempt precipitation. By the way, I was away from the lab for some time, and when I returned I saw that a small precipitate formed, maybe due to...
  2. chem_tr

    Ammonium help

    In aqueous solutions, two types of reaction may occur: 1) Since ammonia is a base, copper hydroxide my precipitate. 2) excess ammonia can give a complex with copper. Please skim your textbooks once again by referring to my clues.
  3. chem_tr

    Decrasing solubility of quaternary ammonium compound in water

    Hello, I have synthesized a compound with two quaternary ammonium groups and two cyanide groups. I did the reaction in dmf, and after the reaction I poured the reaction medium onto ice-cold water. A little precipitate formed, but I think this is not the compound I want, my compound is still...
  4. chem_tr

    Phenol acidity

    I agree. If you are seeking extremes, you might want to add sodium hydride (a very strong base, not needed to prepare phenolate) instead of the commonly used sodium or potassium hydroxide in tetrahydrofuran under 10°C in a controlled manner.
  5. chem_tr

    Feso4 is not a primary standard?

    Hi It cannot be a primary standard. Because it is not stable. A primary standard must be cheap, inert (stable), etc... You may want to do a google search about "primary standards".
  6. chem_tr

    Basicity of NaSH compared to NaOH?

    Hi I think it is less basic than NaOH, since the acidic adduct of NaSH is H2S, where NaOH produces H2O. Since the former product is more acidic, the parent compound (NaSH) must be less basic. Regards
  7. chem_tr

    What is with all the homework question in the chem forum?

    The new forum policy is acceptable, I think the moderators and administrators are seeking more scientific topics discussed right here, other general and strictly homework-related topics are wanted to be posted in another parts of this forum.
  8. chem_tr

    Ahhh! Titanium Chloride

    Yeah, radicalic hydrogen is the best. Isn't sodium borohydride alone (in dilute alcoholic solution, for example) is sufficient in reduction? You might cool the solution to say, 0°C, to reduce its vigorous nature, and quench it with diluted HCl after slowly bringing the medium to room...
  9. chem_tr

    Chemically dissolve aluminum?

    Well, I wonder if you try a redox reaction, such as placing electrodes and using an electrolyte such as aqueous acid solution; with this way you might dissolve it as Al3+ ions and not give harm to the coating. However, it would be wise if you make a little hole inside the wall of the tube, so...
  10. chem_tr

    Has anyone heard of P and M notation?

    Thank you very much. I constantly learn a great deal of knowledge from you. It is very good thing to have you here. To tritertbutoxy: As I understood from Movies' message, it works similar to CIP system; but with one exception: This system is used in chiral molecules with no asymmetric atom...
  11. chem_tr

    Nucleophilicity of Acetylide ion

    Hello, It is possibly because of the fact that pi system in vinyl and extended pi system in acetylide causes the basicity to be lower than that of methyl. Pi bonds tend to love electron pairs, so basicity is lowered. However, please let me inform you that nucleophility is not the same...
  12. chem_tr

    Has anyone heard of P and M notation?

    Has anyone heard of P and M notation??? Hello, A friend of mine has asked a question about a molecule, we think the molecule was a biphenyl molecule with two nitro groups on each benzo unit, along with two carboxylic acid moieties on each ring. So the molecule was shown to be in two isomers...
  13. chem_tr

    IUPAC Nomenclature

    Have you tried examining through the sticky thread on Chemistry forum? I think you will find suitable website there.
  14. chem_tr

    Lewis Structures

    Hello, In case you cannot find your Lewis structures in the site, let me instruct you some basic knowledge. a) Find the neutral valence electron counts of the atoms, and find the total number of valence electrons. In case of negatively charged ions, this value will probably is an odd...
  15. chem_tr

    Interfacing a PC to a UV spectrophotometer

    Thank you, I guess the code includes one "stop bit", one or two "init code", etc. If so, I have a documentation of the old printer mentioning these. Is it possible to use the same settings for the computer?