r/chemhelp • • Aug 31 '26

Discussion Start of term check-in

9 Upvotes

Hello all!

School terms are beginning and this is typically when we see an influx of posts asking for general advice, guidance on getting through a class, or seeking assurance that everything will be okay. Let us know what courses you are in this term, your biggest concerns, or whatever may be on your mind!

Best of luck!


r/chemhelp • • Aug 21 '25

Announcements New Ownership

21 Upvotes

Hello fellow Chemists! I just wanted to introduce myself as the new head mod of this subreddit. A little about myself: I am a PhD Candidate in Chemical Biology. For me, this means that 60% of my work involves organic synthesis and the other 40% is applying my novel compounds to mammalian cells. Specifically, I am interested in early detection of diseases. In addition to my research, I have TA'd for both general and organic chemistry labs and have been tutoring students in organic chemistry for three years. Aside from my academic qualifications, I am also a moderator for another rather large subreddit. I saw that this sub needed a little bit of updating, but it did not seem like the moderators were active any longer. So, I gained ownership through r/redditrequest. I did not realize it would remove all the other moderators, but alas here we are.

Overall, I feel like this sub is fairly self-regulating. I frequently see good discussions and people generally are following the already existing rules. With that said, there are some changes I was considering, and would love input:

  1. New rule prohibiting commenters from solving the problem for the OP. To enforce this, the violating comment can be reported and removed by moderators. I don't see this happen often, but I have seen it occur and put an end to an otherwise good discussion thread.
  2. Mandate students include their work in their submission. Frequently, students post a picture of the question, with no work done and the caption "help please." Then in the comments you end up with people asking the OP to show their work, but from what I have seen they seldom do so. Mandating that students show work would entail removal of low effort posts by moderators. This may not be necessary since generally, commenters request more info from OP anyways, but was curious if people would like to see more enforcement on this end.
  3. What do you want to see? Those are the immediate things I was considering adding, but I would love to know if there is anything else people may want to see. I had other ideas, but I don't want to complicate a sub that I feel is already doing pretty well. Please let me know your ideas, I would love to hear them. Talk to you all soon!

Note: Please do not reach out to me about becoming a moderator. I will looking into recruiting in the near future. For now, I just wanted to get oriented.


r/chemhelp • • 1h ago

Organic Is this correct?

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• Upvotes

This is one of my exam questions, yes there was an extra h2o but idk where it comes from


r/chemhelp • • 1m ago

Organic someone help me understand this bc im legit going to cry (how to know the hybridization kind)

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• Upvotes

First of all yeah my chem background is bad but now I just have to take this course and I’m GENUINELY trying to understand.
So my question is, can anyone please just simplify the rules of how to know what angle the bond has and what hybridization??? Those ochem just piss me tf off I try to look for an explanation they either be beating around the bush or explain really really simple examples and avoids doing the tough ones.
This is one of the questions I got stuck on, it asks for the angle and the what kind of hybridization it is. I basically said it’s 120 degrees (randomally) and I guess it’s a sp^3 hybridization???? Idk I’m so pissed rn and I’m sorry again if I don’t make sense I’m telling u guys I don’t know shit but I’m trying I swear


r/chemhelp • • 13h ago

Organic Meso compounds

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10 Upvotes

I understand that the first molecule with the bromine has a plane of symmetry because both bromine’s are wedged. However, I can’t figure out why the second molecule has a plane of symmetry? The hydroxides are opposite, one dashed one wedged. How are both compounds meso though? I get that to be meso u need 2 chiral centers with each stereocenter being attached to the identical groups . The second molecule shows this, but the orientation in space makes me think there isnt a plane of symmetry internally. Idk if this makes any sense


r/chemhelp • • 7h ago

Organic Question about isopropyl or 1-methylethyl

3 Upvotes

Why do you have to specify that the methyl is in position 1 of the ethyl? If it was on carbon 2, it would just form a propyl, so a methyl can only be in carbon 1 for it to be a isopropyl.


r/chemhelp • • 6h ago

Organic Solvolysis, and alcohol protonation question

1 Upvotes

My textbook said that Solvolysis is only an Sn1 reaction, but other sources say it can be other mechanisms lol, what is true?

And if it is only an Sn1 reaction, does that mean solvolysis will not form any sort of alkene product made by an E1 mechanism? Like zero e1 product whatsoever, not even as a minor product?

Also: after an OH in a substrate is made into a good leaving group via turning grabbing an H and turning into an H2O+ molecule,

how do you know when the newly made good leaving group will break off on it’s own vs. when it needs to be forced out via an Sn2 or E2 mechanism


r/chemhelp • • 22h ago

Organic How to Classify this Molecule and pKa?

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19 Upvotes

EDIT: I'm seeing that this problem I made up is erroneous in all sorts of different ways so I'm asking that this post stops getting new responses. It was my fault for trying to make a problem out of something I didn't understand in the first place. I just took the example off of a pKa chart. Ultimately, I did figure out how to do my work.

EDIT 2: The Nitrogen in the acid/red should have a positive formal charge. I stole the example off of a pKa chart provided by my professor since it had a similar issue to what I was confused about, but the pKa chart was so faded the + looked -. I didn't notice. My apologies guys.

Basing this off of a homework problem I have, so I do apologize if this is crudely simplified. I can also give the real problem in the comments if necessary.

I’m using a pKa chart and estimating the pKa of molecules using functional groups.

Let’s say I have this blue molecule in the image. I see that it has a group which is a conjugate base of the red molecule. I know the red molecule is a strong acid, so the blue molecule is a weak base. Can I consider this molecule a base or neutral? Thinking this through for me at least, because it’s weak, it is unreactive, therefore neutral in an aqueous environment.

Now, the pKa. Can I say the blue molecule has a pKa=5.2 like the red molecule, or should I say the blue molecule has a pKaH=5.2? Or are both wrong statements?

If you’re screaming at me to do an acid-base review, yeah, I am doing one.


r/chemhelp • • 9h ago

Organic please check if this mechanism is correct for the 9-BBN option

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1 Upvotes

i think that the double bond inside ring will not be reduced as it will be hindered by the big structure of 9-BBN and just wanted to confirm if i thought the right mechanism


r/chemhelp • • 15h ago

General/High School Someone please tell me what am I doing wrong

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3 Upvotes

r/chemhelp • • 13h ago

General/High School Solution Stoich?

2 Upvotes

Hello, in my ap chem class we’re learning solution stoich and problems involving molarity and volume etc. and i am just so lost. anyone have resources? thank you!


r/chemhelp • • 13h ago

Organic Why does this alkene have a Z configuration double bond?

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0 Upvotes

In my answer, I said that "a" and "b" are the two highest priorities. Because they are on opposite sides, I chose "E" configuration. My answer key says that "a" & "c" are the highest priorities, making the configuration Z. What am I missing?

Chlorine is obviously the highest priority, but isn't "b" > "c" because the first point of difference bonds to another carbon?


r/chemhelp • • 15h ago

General/High School Is what I am thinking right?

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1 Upvotes

Based on the experimental setup, Beamer B acts as a control that continuously produces Oxygen gas, creating a baseline pressure that pushes the disc to the left. When the disc moves left in Trials 2 and 4, it indicates that Beaker A produced less gas than the control, meaning Beaker A is effectively being compressed and work is done *on* the system (making work positive, not negative). Conversely, when the disc moves right in Trial 3, Beaker A produced more gas and expanded, meaning it did work on the surroundings (making work negative, not positive). Last thing in Trial 1, the disc does not move, indicating balanced pressures with no significant net expansion or compression, which contradicts the statement that work is done on both the system and surroundings. Because every specific claim about the trials violates the standard sign conventions for thermodynamic work and gas production so this is why none of theseis the only accurate choice


r/chemhelp • • 16h ago

Organic help verifying answer - unknown compound given NMR peaks and ESI-MS

1 Upvotes

here’s the question:

“A compound has four sets of 1H NMR peaks, four sets of 13C NMR peaks, and an ESI mass spectrum peak at approximately m/z= 93. What's the name of this compound?“

i’m having an irl version of “billy and sally disagree on the answer to this problem. who do you think is correct, and why?” - but i think it’s benzenamine/aniline but my friend thinks it’s phenol. there’s no answer key but this is a big part of our grade </3

is it either of those or are we both onto nothing? thank you reddit!


r/chemhelp • • 1d ago

Organic Anyone else struggling with Organic Chemistry?

7 Upvotes

I’m currently taking Orgo 1 in college, and honestly, it’s been pretty challenging. I’m trying to get better at understanding the concepts rather than just memorizing everything.
I’d love to connect with other students who are taking orgo or have already survived it lol. It would be nice to have someone to exchange study tips with, ask questions, or just talk about chemistry struggles.
If anyone’s in the same boat or enjoys helping with orgo, feel free to DM me! Always happy to make some study friends :)


r/chemhelp • • 21h ago

Organic Can someone please explain how I convert the beta carotene into the ring?

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2 Upvotes

r/chemhelp • • 19h ago

Biochemisty How does covalent catalysis occur on step 2?

1 Upvotes

when i look at it, covalent catalysis is where the oxygen attacks the C=O. this happens after the step 2 arrow / product of step 2. so shouldnt it be step 3 because it begins at the product of step 2 and the result is shown after the step 3 arrow. furthermore, the acid/base catalysis arrow is is drawn at the same time the covalent catalysis arrow is drawn so i dont understand how covalent catalysis occures on step 2 and acid/base catalysis occures on step 3 when both arrows are drawn at the same time (between step 2 and 3 arrow)


r/chemhelp • • 19h ago

Organic If Ha and Hb are different then would I count them when I use the n+1 rule even if they are on the same carbon?

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1 Upvotes

r/chemhelp • • 23h ago

Organic Idk if I did this right I don’t know how many times I can move electrons per structure

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2 Upvotes

r/chemhelp • • 1d ago

General/High School I don't understand the definition of Gibbs free energy

25 Upvotes

Like I get that from the result we can determine if a reaction is spontaneous or not, but the definition in my textbook says "maximum amount of work a system can do as it approaches the end of the reaction." What does it mean by maximum amount of work? Other definitions are saying how much usable energy is left, which I don't really understand either.

I always assumed it to be how much energy is used during the reaction, but its wrong? If anyone could dumb it down, or just explain it in different terms it would help.


r/chemhelp • • 1d ago

General/High School Problem Chem - Lewis Structure

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2 Upvotes

I really struggle with converting bond-line into Lewis structure and vise versa. Is this incorrect? I feel like it’s right but I’m certainly not trusting my own judgment for this lol. Thanks in advance!!


r/chemhelp • • 1d ago

Organic Can someone explain this step of a Carboxylic Acid/SOCl2 reaction?

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21 Upvotes

I dont see why the molecule would kick off the oxygen as it seems pretty stable and kicking it off creates an unnecessary positive charge

Additionally, im seeing an alternate mechanism online where the alcohol oxygen is the one that attacks, is that one also valid?


r/chemhelp • • 1d ago

Organic Wedge or dash?

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1 Upvotes

When I am doing the nomenclature, how do I know if the R/S is a wedge or a dash? What are the tips?


r/chemhelp • • 1d ago

Biochemisty NAMING NOMENCLATURE

1 Upvotes

Hey! I am still trying to figure out whether is it always important to name a structure alphabetically by its groups?elements? such lets take "4-bromo-1-hydroxy-8-methylphenanthrene-2-carbaldehyde" for an example.....I am a biology major, and we have a presentation that's due tomorrow and I am afraid I'll choke when explaining the naming of derivatives


r/chemhelp • • 1d ago

Inorganic Electron count a zinc compound?

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4 Upvotes

I've been trying to electron count this in the covalent method, but I'm getting differing search results on whether to consider Zn(0) as 10 or 12 electrons, based on whether the 4s2 electrons are included. I assume the 4N donate 2 each and triflate is an x type ligand.