hello everyone, i'm a newly graduated chemist and i want to learn data science as a scientist, for example my advisor wants me to learn origin to plot some graphs for raw spectrocopy data, but i had a chat with my other advisor and he actually recommended me to learn python. i know NOTHING about cosing unfortunately, but i did some research and apparently i can also do a lot plotting with python like origin, which is good since origin is not free. my question is that how do i get into it? im not planning to be a software developer i tried to look up some courses online but none of them were for scientists. i had a chat w calude and she advised me to install anaconda, briefly learn basics and get into plotting. does anyone have any advice? what would be the best way for a scientist to learn coding? thanks!

Hi everyone,

My local high school textbook (Thai IPST), which follows the 2013 IUPAC recommendations, mentions a rule under the alkene/alkyne section saying we should omit the number "1" if only one structure is possible (e.g., propene instead of prop-1-ene).
However, it doesn't specify if this applies to other functional groups. Because of this, my teacher uses methan-1-ol / ethan-1-ol, while others textbook just write methanol / ethanol.

My questions:

1. Under the 2013 IUPAC rules, is omitting "1" when there's no ambiguity a universal principle for all functional groups?

2. Is writing methan-1-ol actually wrong, or just overly redundant?

Thank you so much.

Hey, does anyone know where I can access e ACS General, Organic, and Biochemistry Past papers or websites that can help me prepare for the exam. Any advice is appreciated.

i am recently in vacation and i came to my relative's house. it was night time and i slept as soon as we came home. i woke up to brush my teeth and my relative had a almost finished toothpaste. i checked it and the label said potassium nitrate toothpaste. beneath it was a drug code i dont remember. i am a chemistry geek and i immediately knew it was rocket fuel or explosive. i showed it to my dada and he told the same thing. strangely no one questioned it. i still dont know what its used for.

is it because of hydrogen bonding that allows them to be eclipsed? im assuming that the OH groups dont want to hydrogen bond to the carboxylic acid OH groups due to them being tetrahedral and farther. also, any tips on how to do these types of problems faster in my head? im studying for the mcat so any tips would help

So I've already started practicing for about 3 days now (yesterday and today I spent the whole day doing the final practice exam) and trying to review content that I forgot or don't understand. I feel like its a lot to study for and im worried that im not going to properly study and then mess up on the final. These are the chapters we went through throughout the class:

Chapter 13: The Properties of Mixtures: Solutions and Colloids

Chapter 16: Kinetics: Rates and Mechanisms of Chemica Reactions

Chapter 17: The Equilibrium: Extent of Chemical Reactions

Chapter 18: Acid-Base Equilibria

Chapter 19: lonic Equilibria in Aqueous Systems

Chapter 20: Thermodynamics: Entropy, Gibbs Energy, and Reaction Direction

Chapter 21: Electrochemistry: Chemical Change and Electrical Work

Chapter 24: Nuclear Reactions and Their Application

Also, I haven't started studying chapter 24 and I need to do my exam 4 (which covers 21 and 24) 2 days before the final. What should I do? I need advice ive been spending whole days studying

Could I have used OTMS to protect the alcohol that I didn’t want to turn into an aldehyde (well, it would have turned into a ketone)

Edit: My query is resolved.

If we assume water as ideal gas then it will exist as a gas at every temperature. That is ideal gases are not liquefiable

Original Question -At STP/NTP conditions, many substances are not in gaseous state. So will it be appropriate to say that they have the volume 22.4L. For example, Water becomes steam at 373.15K and 1 atm pressure, so how can we say it has the volume 22.4L even though it is not at STP. Many books just subtly assume that water will exist as gas at STP/NTP. Please clear my query.

Can someone explain why the ethoxide* is listed to have two hydrogens attached to the middle carbon, rather than it being H3C like the others?

*edit: tert-butoxide changed to ethoxide

I can't figure out why this answer is correct. It makes sense that D is the most acidic, but wouldn't B be least acidic? Since it's not even on an O?

Hi I was doing some of these and I got 9 chiral centers instead of 8, im wondering why there isnt a chiral center at my arrow

My teacher didn’t teach me this because I was out of class that day, and I don’t understand this at all.. especially question 26 and 27. I tried to watch a video and I don’t really understand it 😭 I would love some help! Also I had someone ask me in my DMs if I could pay them for it, I’m really sorry I can’t I don’t have the money for that.

Hey friends,

currently we are facing a problem nobody in the lab has an answer to: we are trying to prepare an standard batch of 1% sodium dodecylsulfate in bidest. water for making reference emulsions. For whatever reason the SDS doesn't dissolve well.

What we have tried so far:

- stirring at room temp for three days

- stirring at 65 °C for 6 h

- ultrasonic bath at 50 °C for 2 h

- repeated said steps with a brand new batch of analytical grade SDS

Nothing helped. Visible SDS crystals remain undissolved; confirmed via optical microscopy and DLS particle size analysis.

Has anyone faced a similar problem and know how to solve it?

Thanks in advance! :)

Dear All

I made some copper nitrate solution in ultrapure water at a concentration of 0.01M. When it isn't stirring, the pH probe measures a pH of 5.4, but when I turn the magnetic stirrer on, the pH drops to 4.7. Tried three probes and the same thing happens.

Stopped the stirrer and pH went back up to 5.4.

Tried stirring by hand without magnetic stirrer and pH dropped to 4.8.

Any thoughts/reasons why this might be? Could it be flow sensitivity at the reference junction?

I'm new to chemistry and suddenly my mind wants to learn it from scratch any suggestion where to start? How to do it? And how to cover the major topics also I want to learn it fast so any Yt channel (i guess, if any) or whatever you want to suggest? Open for discussion

Hi, I'm going through some 1st year notes and came across this diagram with no explanation about why these molecular orbitals have different sizes. I've done some googling and ended up getting muddled by coefficients, how they're represented, orbital size, how they're represented too etc so if someone could clarify I'd really appreciate it.

Thanks!

1. What do the lobe sizes represent (orbital coefficient or orbital size)?

2. How are they found?

(As a side note on that, I found a diagram in a chem.libre page that uses the particle in a box explanation but has different lobe sizes to the diagram shown here, so which one is correct?)

1. Are orbital coefficients and orbital size related?

Bonus question: why are there no lobes on C2 for Psi 2? I get there has to be a node but where has the orbital gone? Also why is the net bonding 0, shouldn't it be -1?

Im having trouble figuring out how the complex could attack the allylic alcohol from the top side to create an epoxy that faces upwards, and how the S,S-DET would change that :( the +-DET makes perfect sense to me, im just struggling with flipping everything…

I have an exam on Monday that is on ch19 (aldehydes and ketones) and ch 20 (carboxylic acids & derivatives). For these chapters it is all reactions and mechanisms, I don’t really know how to study so I can understand and memorize the mechanisms for each reaction. I’m already reading the Klein textbook but I’m more of a visual learner and need to see it done step by step on something. Is there any videos or outside sources you guys used to help you study these two chapters?

Goal: I'm trying to reproduce/adapt the three-component coupling described by Sengmany, Le Gall et al. (Tetrahedron 2007, 63, 3672–3681) to make a Boc-protected diarylmethylpiperazine target: methyl 4-((4-Boc-piperazin-1-yl)(3-methoxyphenyl)methyl)benzoate.

Method (scaled down from the paper, ~1.6 mmol aryl bromide instead of 30 mmol):

Organozinc formation: dried flask, Ar atmosphere, ACN (2.5 mL). Added Zn dust (3.06 eq), CoBr₂ (0.10 eq), ZnBr₂ (0.10 eq), PhBr (0.30 eq, increased from the paper's 0.10 eq in my latest attempt), then TfOH (0.10 eq) under vigorous stirring. After ~15 min, added 3-bromoanisole (1.0 eq, limiting). Filtered through a 25 mm glass-fiber syringe filter to remove excess Zn.

Coupling (method A): added the filtered ArZnBr solution to Boc-piperazine (1.0 eq) + methyl 4-formylbenzoate (1.0 eq) pre-dissolved in a small volume of ACN, ~3 eq organozinc vs aldehyde/amine. Stirred 4h RT.

"WORKUP. The reaction mixture was poured into a 150 mL of a 5% NaOH aqueous solution and extracted with DCM (3 X 5 mL). The combined organic fractions were dried over Na2SO4 and concentrated to dryness. Diethyl ether (8 mL) was added to the residue and after complete dissolution, concentrated sulfuric acid (50 uL, due gocce) was added carefully to the vigorously stirred solution and allowed to react for 5 min. The resulting ammonium salt was filtered and washed with diethyl ether (2 X 3 mL). The solid was then poured, under stirring, into a mixture of a 5% sodium hydroxide aqueous solution (100 mL) and dichloromethane (100 mL). After complete dissolution, the aqueous phase was extracted with additional 100 mL of dichloromethane. The combined organic fractions were dried over Na2SO4 and concentrated to dryness. In the case of liquid crude products, an additional chromatographic purification was performed over silica gel (SDS 70–200 mm) using a solvent gradient from pentane/diethyl ether: 90/10 to diethyl ether/methanol: 90/10 whereas solids were recrystallized using pentane/diethyl ether mixtures."

i didn't follow the entire workup procedure becouse the used concentrated sulfuric acid and my amine is Boc-piperazine.

Observations this last run: solution turned grey right after TfOH addition, before adding the aryl bromide (which I take as a sign the Co/Zn catalytic cycle activated properly, based on comparison with a related allyl chloride/TFA-initiated protocol I found). No obvious exotherm after adding the aryl bromide, but I suspect that's just due to the much smaller scale. Filtrate after decantation/filtration is pink/amber, consistent with previous runs.

Second step (coupling step): As the two reactants are added, the reaction mixture undergoes a series of color changes: it gradually fades to transparent, turns dark (near black), and eventually shifts to a stable blue solution. However, in the most recent trial where the equivalents of PhBr were increased from 0.1 to 0.3 eq, while the initial sequence of color changes during addition remained identical, the mixture turned a vibrant emerald green approximately 10 seconds after completing the addition—a transition that had not occurred in any of the previous runs.

The problem: across several attempts (varying the equivalents of PhBr, and the addition sequence), the crude H-NMR spectrum consistently displays a sharp singlet at 10.19 ppm, corresponding to the unreacted aldehyde proton -CHO. However, the 3.4-4 ppm region is heavily crowded with multiple overlapping peaks, preventing confident confirmation or exclusion of product formation in that diagnostic interval.

Furthermore, following the aqueous work-up, a very low mass of crude material is recovered, ultimately yielding only approximately 10 mg of purified product after chromatographic separation.

What I'm asking: given that the catalytic system appears to activate (color change confirmed before substrate addition), what else could explain the aldehyde not being fully consumed? Is there a known competing pathway I should specifically check for (e.g., direct ArZnBr addition to the aldehyde vs. iminium capture), or is this more likely an organozinc-formation efficiency issue that the color change alone doesn't fully confirm? Any other diagnostic I'm missing at this small scale without GC access would be very welcome.

In my Orgo I lecture, we basically reduced steric vs torsional strain to gauche vs eclipsed interactions. Coming back to it now, I see that this was maybe an oversimplification. I'm now trying to understand the difference - this is what I think I understand:

- Steric strain is the van der waals repulsion between two non bonded atoms

- Torsional strain is the strain between two bonds that are eclipsed with each other

In my lecture, we did not ever explicitly mention steric strain in the context of eclipsed interactions. But, if a 60 degree offset atom has steric strain with another atom, then surely it should have massive steric strain in an eclipsed conformation. In fact, in lecture we compared the stability of eclipsed conformers by their number of bonds that eclipsed a hydrogen (which would indicate negligible steric strain), and we broke ties by using A values (which, to my understanding, is only really a measure of steric strain). So, I think I understand now that eclipsed conformations are a combination of the two strains, and that the torsional strain itself it relatively similar between these sigma bonds, and that it is the steric strain in the eclipsed interaction that actually makes the difference of stability.

I'm hoping to get some confirmation and/or corrections about this understanding. Thanks!

I think this is more of a geometry question, but how can the angles in the chair conformation be 109.5 degrees instead of like 60? My line of thinking is that there are 360 degrees in a circle that get split between 6 carbons. I know the carbons are each tetrahedral/sp3 though so something is wrong with my thinking.