Got this question wrong and just looking for some clarity. Exam next week so I want to get my act straightened up 😅 Thanks in advance for any help!

I know how you name this one, but ive got a question. The chain bound to the ester's oxygen is numbered starting from the left, but is that always the case, that you start numbering from wherever the ester's oxygen is, or do you take the numbers to grab the substituents with the lowest numbers. This example is not very good because you would start from the left whatever the case is.

This reaction comes from a uk chemistry Olympiad question. I can’t figure out what causes the double bond to move, along with the mechanism for the decarboxylation, it’s different from what I’ve seen before with beta keto acids.
If anyone knows the mechanism or of similar reactions it would be super helpful.

I need help coming to a conclusion about this problem. I’ve asked TA’s and grad students but no one agrees with me and I swear I’m right. So this homework problem came up for me and I thought that protonated carbonyl(on the left) should be stronger than the sulfuric acid on the right, so that the equilibrium shifts to the left, but this was wrong. In the explanation they gave us, it cites that sulfuric acid’s pka is -9 and protonated carbonyl is -7. But sulfuric acid’s pka is -3, so this is wrong, right?

So shouldn’t I be right? It doesn’t make sense to me why I’m wrong but people keep telling me that sulfuric acid is a strong acid and that its conjugate base has more resonance structures, so it’s more stable. But protonated cyclohexanone’s conjugate base is completely neutral, so isn’t that most stable?

Everyone I ask has agreed with the problem, except for me, and I don’t know why. Am I wrong or is it because people recognize sulfuric acid better and go with that?Please help me, it would be very appreciated. I tried emailing the professor but she has not responded. If you could include your reasoning because I need to know what I should be thinking on an exam. My TA just told me to memorize the basic strong acids, but that doesn’t make sense to me.

this is a pinacol to pinacolone reaction. the problem is that which one OH will be protonated first because i'm seeing 2 factors here
1. there are 2 more ɑ-H on left than that on right to stablise the carbocation

2.the rxn is SN1 which has primary factor- ease of dissociation and secondary factor- carbocation stability and by that you can see the 2 ethyl groups will push more on right
which one will get protonated first and take the rxn forward???

I don't know which carbon to start from, would it be 3-tert-butyl-3-ethyl-1,4-butanediol? I'm genuinely confused

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

Please be gentle with me.

I want to buy this distillation apparatus, but the Smart Lab people have sent me an email to say that they don't have what I'd need to distill water. I am so confused. We have very 'mineralised' water here where I live, and I was hoping to distill it in order to simplify my life a wee bit.

Here's the link to the apparatus: smartlabs.co.za/products/distilling-apparatus-with-ground-in-glass-joints-1000ml

How do you know what the limiting reactant is without the pic?

I just need help with determining which is more stable between A and D. The others are more apparent in their ranking as E has vinylic radical, and B and C have to do with Resonance.

I am doing an experiment with STM and have to use Gwyddion to determine the grain distribution. As it is my first time using it, I am not entirely sure how the mask is supposed to look like and google is not being particularly helpful.

I used the water shed feature as recommended by the assistant. The experiment had us look at gold sheets.

The 1st picture is without the mask and the second one is with it. I think that the lines are correctly placed, but the graph that came out for it was rather jagged.

Thank you in advance for your help.

I have an exam coming up and safe to say I did very badly on the practice quiz. A more full list of what I need to know looks like this (aka what I’m getting lost on)
-when are double bonds possible

-recognize when resonance structures are possible, and draw all

possible resonance forms

-calculate formal charges for atoms and include these on structure

-calculate formal charge

select the greatest resonance contributor

• use VSEPR and the Lewis structure to

-correctly identify shape and bond angles

-sketch geometry using a simple line-drawing

-predict the overall polarity of a molecule (using both ΔEN and geometry)

-predict the hybridization of a specified atom in a structure
-determine the number of σ and π bonds in a given molecule

-explain/describe the formation of double and triple bonds in terms of σ and π

bonding

-describe the bonding in a simple covalent species in terms of the bonds and

hybrid orbitals involved
I know It’s a lot but my textbook is not very good and my professor mainly puts photos on her slides, I’m super lost and don’t even know where to start.

I have a solution I’m running an NMR on. My solvent is DMSO-d6 but my compound has a few amines. To ensure my peaks are correct, I added a few drops of D2O to check them. However, in doing so, I found that a triplet, one I did not associate with the product, also disappeared. I thought the only peaks that would disappear were singlets (i.e. exchangeable protons like -SH, -OH, and -NH2). Can anyone help explain what is going on?

Hello Gen chem 1 here. I’m trying to figure out balancing chemical equations doing okay so far. But now confused on what the heck these parenthesis mean.

See that’s the thing with chem man there’s always a bunch of tricks and more steps. Once you think you have it figured out this type of stuff starts popping up😂

I have a solid mixture of two substances, one of them having a pH of 4.2 when at a concentration of 5 percent in a solution and one of them having a pH of 5.3 under the same circumstances; how would I go about isolating them? I know that I have to pulverise the solid and form a solution with it, and I know that somehwere along the road I'll probably have to use dichloromethane or chloroform, but that's literally all I know. Can anyone help?

I’m very confused with this. I’ve been good and understand the chemical balancing of a normal equation. But now I’m trying ionic ones and getting confused. In order to complete these do I need to know the charges of some transition metals? Like lead, copper ect? Is that how this was done.

Not sure if my question makes sense or not. But is this also an oxidation question? Or is ionic equation different than oxidation reactions

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

I came up with 1,4 bi-isobutylene-heptane (a) and 1-isobutyl-pentene (b). Am I close? What might I be doing wrong? Thank you.

I got an exam tomorrow for pchem and for the life of me, I cannot get these two topics. (I feel really good about the rest of the topics) I know a (degree of disassociation) is like the percentage of how much is taken away(?), but I feel very iffy on that. maybe I'm slow but I don't understand IE tables. does anyone have links to videos? i don't think the organic chemistry tutor made videos on physical chemistry and I cannot find any videos on pchem. lol thank you!

Hi yall, im in college right now—my second year—and I’m doing so horribly in chem. I want to be premed but my grades are abysmal (like C+ B- range and I know I need to be at least a B+, ideally A). The first year I was only sort of locked in and I did all my assignments and homework but I didn’t really go to office hours that much. On those exams I always did pretty poorly even though I felt like I mostly understood everything. This year I wanted to turn it around. I arranged tutorings twice a week, I went to office hours, and I studied for hours each day. I basically had to relearn a lot of basic fundamentals but now I’ve gotten to the point where I can actually follow along in class and understand what my professor is saying. I felt so proud of myself for reaching this point—for catching up to the point I didn’t feel like I lagged behind so much. Anyways, I checked my first exam grade the other day and it was actually trash. Like 50%, I failed that exam no questions asked. I feel so bummed too. I knew there’s no way I got everything right but i felt like I understood most of everything and it just sucks to see that after I spent so long studying and building confidence. I feel horrible too because I was trying to build rapport with my professor and joke a bit with him in between office hours (like saying I really liked his pets that he showed to the class and I shared his music tastes). Now I just feel embarrassed because I was so confident and my test score had nothing to show for it. I want to talk to my professor and get advice but I’m worried I won’t be able to control my emotions and leave our conversation in an awkward spot.

I think the worst thing is, I’d always functioned on the mindset that hard work leads to good results and if I work hard, I’ll do well. If I’m doing so poorly, does that mean I need to work harder? Maybe I’m not studying right, but I feel like through my studying I’ve genuinely developed a more complete understanding of mechanisms and reactions and why things happen rather than that they simply do. It’s gotten me to the point where if I’m stuck, at least I know basic starting points to work off from (like how an acid will more often than not, protonate. So if I have an acid and an OH in my starting material, there’s probably going to be pronation happening). My next exam is coming up soon and I’m so nervous and anxious that I’ll do poorly again and won’t be able to have my upward trend I was aiming for premed.

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

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.

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.

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

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