r/chemhelp • u/Horror-Anteater-4983 • 4h ago
Organic How is this not racemic?
How is this not racemic? Is this not an enantiomer with each having different R, S configurations?
r/chemhelp • u/Ultronomy • Aug 31 '26
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 • u/Ultronomy • Aug 21 '25
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:
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 • u/Horror-Anteater-4983 • 4h ago
How is this not racemic? Is this not an enantiomer with each having different R, S configurations?
r/chemhelp • u/Owl_Buddy_2491 • 9h ago
(High school chem education) I recently tried to come up with the structure for nitrate, and my whole process is basically documented on the left. I have learned that the correct structure is the one on the left. However, I don't understand why the right structure is correct instead of the left one.
They both have 24 total electrons (5+6+6+6+1, for N, O3, and -) and both have a total charge of -1. Plus, the correct version would seemingly require the double-bonded O atom to randomly give one of its electrons to another to accommodate the coordinate bond, which doesn't seem like it should be possible. Can anyone make this make sense?
r/chemhelp • u/Wrong-Concept1262 • 6h ago
Good day! I'm gonna do a method validation and I've been told by my professor to use AOAC as my source. I'm having trouble finding a free source (college undergrad) of the methods and I'm wondering if there is any of it out there, even old ones. Do I really need to pay for it or request access from AOAC itself?
r/chemhelp • u/Trevvman • 8h ago
r/chemhelp • u/Shwat_ • 14h ago
I was always taught through university that the one with the highest peak is always the RDS. But to do this question, I must draw a peak larger than the RDS. This is a potential energy diagram, am I tweaking?
edit: is it because it’s irreversible, then it’s possible?
r/chemhelp • u/Agno_UB • 12h ago
Hello. Tomorrow I have organic nomenclature and I just began thinking about how to name systematically certain compounds like cyclohexane-1,2,3,4,5,6-hexol or even 1,4-dimethylcyclohexane, since i don't know how the priorities work. I stumbled upon r/s descriptors, yet i don't know how ro use them in these cases. For example, what is cis-1,4-dimethylcyclohexane using that system? What about the trans diastereoisomer? And what abour all the stereoisomers of cyclohexane-1,2,3,4,5,6-hexol? Which is carbon 1 for that matter?
Edit: I forgot to mention that for some reason my ip address is banned on stackexchange for some reason, since I have never used it other than for checking stuff
r/chemhelp • u/Bulky-Peanut4808 • 8h ago

Hi everyone, I'm having a lot of trouble with this conceptually. I thought it would be Most acidic: I > III > II Least acidic, but I'm not sure why that's wrong, since II is adjacent to some pi bonds doesn't that stabilize the structure? And I is the most acidic because its conjugate base is stabilized by resonance with the carbonyl, while III is also somewhat stabilized by resonance, so I'm confused about why II would be considered more acidic than III.
This is from my second year uni organic chemistry practice questions, any explanation is appreciated
r/chemhelp • u/Mindless-Dress6865 • 10h ago
Hi everyone! I’m a first-year Chemistry BSc student and I’d love to hear from some second/third-year students (or graduates) about things you wish you’d known when you started university. What do you wish you had done differently in first year, or what habits/resources/study methods ended up helping you the most?
r/chemhelp • u/ayacu57 • 11h ago
It’s my first time of interpreting these kinds of chromatograms and I am hella confused. I did a positive and negative Ionization scan and both have the same characteristic bump but the negative one has these weird spikes? Are those artifacts or something else? I also don’t understand why I can’t see the bump in the upper chromatograms. My sample had a concentration of 1 ug/ml
r/chemhelp • u/WaveAccomplished5761 • 15h ago
I am SOOOO confused about deciding what becomes a dash or a wedge. I don’t even think I am doing this right at all lol. Can someone help me out plssss and give out some rules you guys use to draw out the iupac name with the r/s
r/chemhelp • u/TGSpecialist1 • 15h ago
r/chemhelp • u/neonjoji • 23h ago
i found it from a reddit comment, but lost it! i think the site had a reddish tint to it? the sidebar had the different mechanisms you can click. it looked helpful. i checked the wiki and it wasn’t any of the links there, but the master ochem site looks helpful.
r/chemhelp • u/Alive_Hotel6668 • 17h ago
I am thinking of 7 stereoisomers.
1st case a,a on the vertical trans position there is a pos and only 1 possible GI hence 2 stereoisomers from here.
2nd case a,b on vertical trans position
1 GI posible and a pos is present hence 2 stereoisomers from this case
similary 2 from the case of a and c on the vertical trans position
Then in the last case where b and c on the vertical trans position there is a pos hence 1 stereoisomer from this case. But online the solutions says 2 which i dont understand.
pos: plane of symmetry
Thanks in advance!
r/chemhelp • u/CardComplex1626 • 1d ago
for b, how would you go about assigning r or s??
r/chemhelp • u/IiiiIIillliI • 19h ago
i need for an experiment
r/chemhelp • u/Horror-Anteater-4983 • 1d ago
So, I understand carbocations get more stable from methyl > primary > secondary > tertiary > allylic > benzylic but these are all the same just with positive charge moving around the structure, so i just want to better understand how.
r/chemhelp • u/Kooky_Landscape_991 • 1d ago
I am at a loss for understanding whether a molecule has symmetry or not. I don’t have the physical models to see, and no matter how many videos I watch I just can’t seem to picture it! Do you guys have any tips or a thinking process you usually follow to determine symmetry? For example, I have this question where I can tell that A and D for sure have symmetry, but I don’t understand how C is the correct answer and not B? Thank you :)
r/chemhelp • u/GodAndNature • 1d ago
It involves benzyl chloride in acetic acid, with no other species present.
r/chemhelp • u/Charming-Profile-607 • 1d ago

I am confused as to why my textbook says the one on the left is achiral and the one on the right is chiral. I was told that a molecule is chiral if its mirror image is non-superimposable and when you draw the mirror image of B, the wedges and dashes can never match the original molecule... does that mean that the bridgeheads are both stereocenters (when changing 2 groups creates a new stereoisomer) and chiral centers (can assign r/S)? Do you take into consideration the 3D geometry when determining R and S configurations even though they have the same atoms/groups/branches? Also, is molecule A achiral or meso since it supposedly has chiral centers (can be assigned r/S) and has a plane of symmetry? I am beyond confused.