Jump to content

adianadiadi

Senior Members
  • Posts

    40
  • Joined

  • Last visited

Everything posted by adianadiadi

  1. Both are same. 2nd one is another way of writing the same molecule. Hint: when you exchange to bonds with each other, the configuration is inverted i.e. from R to S or S to R.
  2. We know that Grignard reagent is strongly basic. It is stronger than NaOH. We also know that sodium hydroxide is just enough to abstract a proton from active methyl group of acetaldehyde to carry out aldol reaction. Now my point is, if we use Grignard reagent, acetaldehyde should undergo aldol reaction instead of Grignard reaction. Any comments?
  3. I think HCl is not the best option to lower the pH. We should use other weak acids like acetic acid (Vinegar)
  4. Yes bonding between the pan and food or degraded food. But what is the nature of those bonds. Exactly what are they?
  5. A simple periodic table with salient features explained can be found at: link removed
  6. Whether a hard acid is a stronger acid? I mean if we take soft acid, is it weak?
  7. It is possible to extract caffeine from tea powder using carbon tetrachloride. In fact tea powder has more caffeine than coffee beans. As far as I remember, the extraction goes smoothly. Final crystallization with charcoal will give the pure crystals.
  8. Sorry to interfere, after a long time, however, I do not see any bond breaking between red and green labelled carbons so that it will make spiro carbon planar. Could you please clarify this? Please try to mark the bonds instead of atoms. Thank you.
  9. During the haloform reaction, the base hydrolysis of α,α,α-trihalocarbonyl compound gives the haloform as the final product. But why not the halogen groups are substituted by the OH- groups to give a trihydroxy compound which can lose water molecule to give finally an α keto acid?
  10. What is the name of isomerism exhibited by methyl acetate and ethyl formate. Both are esters. So not functional isomers. Do you call them metamers or something else?
  11. You can learn chemistry just by asking yourself some basic questions. Is it so you by heart other subjects and it fails when it comes to chemistry? Do you ever try to understand this subject? Try at basic levels. Listen to your lecturer carefully. Revise by practicing the subject. Adi
  12. Hint: Adjacent axial or equatorial positions are trans to each other. Alternate axial & equatorials are also trans to each. Remaining you have to work out. You have to visualize the cyclohexane first.
  13. Any idea of separating Urea from Formic acid from their mixture? Both are water soluble.
  14. "The positive entropy change is thermodynamically not favored" is not correct. According to second law of thermodynamics, all the spontaneous processes involve increase in entropy of universe.
  15. I think there is no reason. In my lab I found absolute alcohol in plastic bottles.
  16. I think MgBr+ might be written in the equation showing Grignard reaction. This species represents Mg2+ and Br-. But these ions exist in the aqueous solution separately.
  17. I would like to add one more upcoming site: AdiChemistry
  18. They are not taken as constants. But for pure solids the activity is taken as one. For liquids and gases, it is not one. The activity of solids is one because the active surface of solid which can take part in the reaction is almost negligible when compared to the liquid and gases. But what about for finely divided solids? Is the active surface area still negligible when compared to that of liquids and solids?
  19. Grignard reagent is formed from an organic halide and magnesium in ether solvents. But they are highly basic and hence can react with protic compounds like aniline or phenol. Hence they wont give grignard reagents. Read more information about this at Grignard Reagent by AdiChemAdi
  20. The number of valence electrons in boron is 3. Among them, one electrons is contributed for B-H bond at the vertex. The remaining 2 electrons are invoved in skeletal bonds formation and are termed as skeletal electrons (SE’s). That is why contribution of each B-H to skeletal electrons is 2. Likewise, carbon contributes 3 electrons to skeleton. * a closo-deltahedral cluster cage with ‘n’ vertices requires (n+1) skeletal electron pairs (SEP’s) which occupy (n+1) cluster bonding MOs ; It also implies, the skeletal electrons (SE’s) must be equal to 2n+2. (i.e. n vertices require 2n+2 electrons in closo cluster) * Likewise, a nido-deltahedral cluster cage with ‘n’ vertices requires (n+2) pairs of electrons and so on. n+1 condition is satisfied only with closo anions and hence more stable. Note: Here the value of ‘n’ represents the actual number of vertices in the cluster (or the number of boron as well as carbon atoms). According to some textbooks, ‘n’ represents the number of vertices in the parent closo cluster. You will get more from boranes topic at AdiChemAdi
  21. I would like to introduce you a new site with chemistry content especially with named organic reactions section. It is an educational site with good chemistry articles base. You may go through the named organic reactions at following link: http://www.adichemadi.com/organic/namedreactions/contents.html Some named reactions covered are: Michael addition Bamford-Stevens reaction Cannizzaro reaction Favorskii rearrangement Phillips condensation reaction for pharmacy students Adi
  22. You may add an upcoming new site http://www.adichemadi.com/ also to this list.
  23. Will you post the exact problem. Your question is not clear. How do you figured out there are 100 g of glucose?
  24. Bamford-Stevens reaction is added to the list. Get it at http://www.adichemadi.com/organic/namedreactions/bamfordstevens/bamfordstevens1.html
×
×
  • 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.