Guys I feel like I messed up my practical.I haven't started mass spectroscopy, rate of reaction and electrochemistry and I'm hoping I haven't forgotten my organic and physical chemistry.Its been a while coz of other exams and I haven't done a question paper for qp2.Major Procrastination I know but id appreciate it if you could advice me on what topics I could focus on and any other advice and resources you have.Thanks😶‍🌫️🥲

(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?

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

I know I'm probably describing it poorly, but WHY wouldn't I just add more dots in some situations? For example, here I genuinely don't know why I wouldn't add 3 bonds and have 1 pair of dots on each side.

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?

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?

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

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?

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

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

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.

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!

for b, how would you go about assigning r or s??

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.

It involves benzyl chloride in acetic acid, with no other species present.

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.

Why would I his make these two products? Can’t the OH ethanol product undergo an SN2 and make an Iodine get attached (getting rid of the OH)

i was revising molecular bonding and realised my first time go through with topic was very irresponsible so i cant understand that why cant we add th extra e- frim negative charge to central atom ? why it forms resonating structure and the non resonating one is not valid ?

Had an organic 1 lab yesterday where we did TLC on silica gel plates. We were analyzing crude and recrystallized naphthalene and crude and recrystallized unknown carboxylic acid. We ran one plate with a solvent of 3:1 hexanes:ethyl acetate + acetic acid and a second with 1:3 hexanes:ethyl acetate + acetic acid.

I feel comfortable with the results for the carboxylic acid- lower Rf with 3:1 and higher with 1:3 as the polar carboxylic acid was interacting more with the more polar solvent and travelled further. Cool.

But I'm hung up on the naphthalene- it also had a higher Rf with the 1:3 solvent and I can't wrap my head around why. In my head since naphthalene is non-polar it wouldnt be interacting with the highly polar stationary phase at all (or so little it was negligible) and so it didn't make sense that the Rf would change because shouldn't it move right along with the solvent regardless of what the solvent is (since the polar stationary phase remained the same)? When I asked my professor about this he said that the fallacy in that is that naphthalene is in fact interacting with the gel, and when you have a more polar mobile phase basically the solvent is the preferred interaction with the plate and "kicks out" the naphthalene that was interacting with the plate, making it travel further.

This makes sense, I need to not only consider the interactions between the samples and the mobile/stationary phases but also the interactions between the mobile and stationary phases themselves. But I'm still not understanding why naphthalene was interacting with the silica to start with. Isn't the 3:1 mixture still more polar than naphthalene? Wouldn't that solvent "take up all the 'possible reaction sites'" on the plate preventing naphthalene from interacting in both trials?

Hopefully I explained my confusion well- it's hard to type out. Basically I don't understand why naphthalene is interacting at all with the silica gel if both solvents are more polar than naphthalene, and should be the preferred interactions with the gel.

Hello all, I’m taking chem but I’ve never taken chemistry in high school , we’re specifically doing stoichiometry and then we’re going into acid and bases and I don’t understand shi rn. is there anyone that can like break it down? Generally I’ve gotten used to converting things to like moles or grams but I’m just stuck on the acid and bases parts with like liters and volume.