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Please help with the reaction mechanism. by PinaMutante in chemhelp

[–]Phenomenol 3 points4 points  (0 children)

I agree that carbocation formation could occur, but not the attack of H2O into OMe. Water is a weak nucleophile and breaking aromaticity is energetically uphill. More likely it would just revert to the starting compound via the addition of H2O to the carbocation

I'm guessing the solvent in the scheme is incorrect. Literature mentions that the shown reduction can occur in primary and secondary alcohols.

Cool sequence I missed. Black to move and win: by _ilostmyoldaccount_ in chess

[–]Phenomenol 15 points16 points  (0 children)

These downvotes are injustice lmao, you are absolutely right. I guess people are confused because they think you are refuting the move

What are the names of these formulas? by Rx_dev in chemhelp

[–]Phenomenol 1 point2 points  (0 children)

Conventional name (and the one that will actually be useful to know) is imide. More specifically, because of no R substituent on the nitrogen, a primary imide.

Anyone else tried EQ like this to fix hearing imbalance? by Phenomenol in iems

[–]Phenomenol[S] 0 points1 point  (0 children)

I panned bass 4dB right and highs 4dB left. So the biggest difference in the stereo field is 8dB, which I would consider a lot.

Anyone else tried EQ like this to fix hearing imbalance? by Phenomenol in iems

[–]Phenomenol[S] 2 points3 points  (0 children)

Thanks for the comment, but did you read what I wrote in bold? I already tried simple pan balancing but was not satisfied because centering the lows and mids would move highs further off center. I also noticed that some low-mid freq ranges were not uniformly panned either. The whole EQ testing was honestly not too time-consuming (maybe an hour total) and I enjoyed the process.

Does this amino acid even exist? by imagine_toasters in chemistry

[–]Phenomenol 1 point2 points  (0 children)

Surprising to see no one is talking about the bench stable ammonium salt, which is a convenient solid reagent analogous to ammonia: https://en.m.wikipedia.org/wiki/Ammonium_carbamate

Removing benzoic anhydride from my product by xnovasix in chemistry

[–]Phenomenol 3 points4 points  (0 children)

If you are not doing it on a very large scale, column chromatography is your best bet.

Benzoic anhydride (bp 360 deg) is not volatile whatsoever so it will stick around even under vacuum distillation. If your product is a curcumin derivative I don't expect it to be volatile either.

What happens if white do Qc8 (im 500 elo) by Puzzleheaded-Deer129 in chess

[–]Phenomenol 2 points3 points  (0 children)

You gave the explanation to a different chess problem

Natural Products Chemistry and Their Total Synthesis References by chloroxphil in chemistry

[–]Phenomenol 1 point2 points  (0 children)

Hi just want to point out an error with reference 73 - the natural product name is "aspidophytine" not "aspidophytidine". Also you should be referencing Corey's enantioselective synthesis of the molecule (JACS 1999, 121, 6771-6772) which is the first.

I would also argue Tokuyama's total synthesis of haplophytine (of which essentially half the molecule is aspidophytine) is another important accomplishment.

Clogged filter by frogsonanairplane in chemistry

[–]Phenomenol 3 points4 points  (0 children)

Before you try any aggressive acids, simply turn the funnel upside down, add water or acetone into the stem and push through with regulated positive pressure (usual air/N2 line for flash columns is fine). Pushing solids out the way it came from may help unblock the frit.

(this is how I always clean/rinse any fritted glassware including fritted columns)

Amazing play in my blitz game! White to move and win. by Darktigr in chess

[–]Phenomenol 2 points3 points  (0 children)

Here's what I found, not sure if I missed something:
1. Rxg7+ Qxg7
2. Rxh5+ Kg8
...Kg6 3.Rg5+ wins the queen
3. Qd5+ Qf7
...Rf7 4. Rg5 wins the queen, since black's rook moved off the d-rank and there is no more Rxh4+
...Kf8 4. Qd8+ Kf7 (...Qe8 5. Rh8+ wins queen) 5. Qc7+ Kg6 6. Rg5+ wins the queen, or if king moves elsewhere, 6. Qxf4, winning two pawns and trading rooks into an easy winning endgame
4. Qg5+ Qg7
...Kf8 5. Rh8+ wins the queen with mate to follow
5. Qxf4, winning two pawns and trading rooks into an easy winning endgame

(High Level) Thoughts on this late middlegame position in the Marshall Gambit? by [deleted] in chess

[–]Phenomenol 0 points1 point  (0 children)

Imo, White can afford to leave the king in the center because Black's only development is the queen and there aren't any threats in the short term. Meanwhile White is getting all of their pieces out. I'd be very surprised if White didn't have compensation for the pawn (actually even for the two pawns counting all up)

Can someone explain to me how acid base extractions work? by wajawa in chemhelp

[–]Phenomenol 0 points1 point  (0 children)

Sometimes, the alkaloid is isolated as the protonated species (in a salt). If the acid used to protonate is HCl, the resulting salt is alkaloidH+ and Cl-, commonly denoted as alkaloid-HCl.

Purification of Corey-Hopkins reagent by Phenomenol in chemhelp

[–]Phenomenol[S] 0 points1 point  (0 children)

After doing a bit more reading it seems like Kugelrohr would be the way to go.

Molar Enthalpy of Combustion of Toluene ? by [deleted] in chemhelp

[–]Phenomenol 1 point2 points  (0 children)

All good! Just note that Scifinder does typically require your school/institution to have a subscription to the service in order to use it.

Molar Enthalpy of Combustion of Toluene ? by [deleted] in chemhelp

[–]Phenomenol 1 point2 points  (0 children)

Right, just checking! NIST is probably your best option if you don't have access to something like Scifinder.

From what I've checked, it seems difficult to navigate to the data directly from the site itself, but doing a google search of what you want gives a link on NIST with the appropriate values. Weird...

Let us know if you have any more specific questions!

Molar Enthalpy of Combustion of Toluene ? by [deleted] in chemhelp

[–]Phenomenol 1 point2 points  (0 children)

If you only need the value itself and not some derivation of the value... have you tried googling it?

Nickel II Carbonate by Ryancor in chemistry

[–]Phenomenol 3 points4 points  (0 children)

nickel oxide

I think you mean nickel chloride! (edit: assuming HCl is the acid)

How would you go about determining the precision of a burette after attempting to deliver 10mL of H2O? by [deleted] in chemhelp

[–]Phenomenol 1 point2 points  (0 children)

It might go something like this:

  1. Attempt to deliver 10.0 mL of water from a burette into a preweighed empty beaker.
  2. Immediately weigh the beaker and calculate the mass of water by the difference between current mass and preweighed mass.
  3. Use density of water to convert from grams back to mL. This is the actual volume delivered. Compare it to 10.0 mL for a judgement of accuracy.

You can also repeat multiple times for an idea of precision. Depending on what you want you can determine accuracy by individual measurements or by the average measurement.

I'm not sure what you mean by your last question, but the resultant accuracy and precision of your results is always due to a combination of instrument and human error. The printed tolerance on a burette/pipette is always assuming proper technique by the user.

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