FMLSA- For selecting parent chain is the first priority including as many principle functional groups(from acid to amines order) as possible or picking the main principle functional group in this case carboxylic acid then does the priority shift to max number of multiple bonds. In this question which parent chain is correct. Plz help ,gemini just switches bw 1 and 2 if u ask the doubt twice

Does this method work without exception, to show that Chiral Carbons are always nonsuperposable with their mirror image, and Carbons that aren't Chiral carbons, are always superposable with their mirror image?

There has to be 4 different substituents, and

Ignore the chirality of any substituent that is not part of an enantiomorphic pair. (this is important when you have a pseudoasymmetric carbon where the non-enantiomorphic ligands are not both achiral).

(There's 2 cases of pseudoasymmetric carbon. One with two achiral ligands, and one where you don't have two achiral ligands). All pseudoasymmetric carbons should come out as being not chiral carbons. So, superposable with their mirror image.

So for C3 of Arabinaric Acid. C3 is achiral and not stereogenic. Not a pseudoasymmetric carbon. There aren't 4 different substituents. It's like Caabc. There's a Carbon with two Rs,(with identical constitution), and an H and an OH. So we see it's superposable just from the first criteria, testing whether or not there's 4 different substituents. There's not 4 different substituents, two are the same, so it's superposable. Not chiral.

For C3 of Ribaric Acid . It's a Carbon with exactly 1 enantiomorphic pair of substituents R,S. And an H and an OH. That's pseudoasymmetric with two achiral. CabRS There's a plane of symmetry there across that Carbon.

Let's say we want to test a pseudoasymmetric case with a chiral and an achiral ligand. So If we replace the OH in Ribaric Acid with a chiral substituent like C Br I H, then to make this work, it's important to ignore the chirality of both non-entnatiomorphic substituents,, so treat it as if it has two achiral substituents, CabRS, there's a plane of symmetry there across that carbon. So it's not a chiral carbon. It's superposable.

It seems to me that Chiral Carbon is really about Capital R / S stereogenicity.

If we have a carbon with two enantiomorphic pairs, then that's just a carbon with 4 different substituents, nonsuperposable with its mirror image. Chiral carbon.

So it's simple for when there's zero or two enantiomorphic pairs. When there's one enantiomorphic pair then it's pseudoasymmetric and thus not chiral. And The two non-enantiomorphoc ligands might be a)two achiral b)an achiral and a chiral or c) two chiral. (So one can say 3 cases for pseudoasymmetric). Whichever case of pseudoasymmetric it is, it won't be assigned capital R / S. Technically 'b' and 'c' are really nonsuperposable but if we are saying chiral carbons are nonsuperposable with their mirror image, and carbons that aren't chiral carbons, are superposable, then we have to treat all pseudoasymmeteric carbons as if they have two achiral substituents.

If one is going to say that Chiral Carbons are nonsuperposable with their mirror image, and carbons that aren't Chiral Carbons(what one could call achiral carbons),, are (locally) superposable with their mirror image, then that's what one has to do.

I've seen some way we shouldn't even talk of chirality locally or that one should but shouldn't talk of it being to do with nonsuperposability. but if one is going to speak of chiral carbons and their nonsuperposability with their mirror image, then I think it can be made to work by that method.

Is there any counter example to the method I mention, where it doesn't work?

I think really the capital R / S stereogenicity is about seeing if there's anything local to the carbon, causing symmetry.. if there isn't then it gets assigned capital R / S. So then it makes sense to say for pseudoasymmetric carbons even where the non-enantiomorphic ligands are achiral and chiral, or two chiral , you ignore the chirality of those ligands, because they have nothing to do with the carbon you are looking at. Whereas if there is exactly 1 enantiomorphic pair of ligands on that carbon, then having ignored the chirality of other two ligands, you have a mirror plane.

I think it would be simpler to speak of Capital R / S stereogenicity rather than local chirality, or local superposability, (It's assigned capital R / S if there's 4 different substituents and it's not pseudoasymmetric. So 4 different substituents and either 0 or 2 enantiomorphic pairs). But since the Gold Book definition of chirality centre does mention (local) superposability, i'm looking at that, and I think, if one were to take the Gold Book definition seriously, it could be made to work.

Is there any counter example to the method I mention?

Thanks

I have fully read Zumdahl. I've seen that Atkins Chemical Principles and Zumdahl cover the same material but in a different way. Should I learn the new material in Miessler and Tarr? or not. Please suggest other textbooks that can be better for physical, inorganic, and organic. I am currently reading Klein Organic chemistry.

Hello everyone

I'm not sure if this is an appropriate question but I need help to study chemistry effectively. I'm in grade 11 and this year things got a lot more elaborate and complex and I often struggle keeping things in mind, especially exceptions to certain things and I struggle with numerical questions.

Also it doesn't help with the fact that my teacher skips topics and finishes chapters that should take 3 weeks in 4-5 days and her grading is inconsistent.

Regardless of these factors, I have exams coming up in a few weeks and I'm not sure what to do. What worries me more is that I'm not finding any joy in trying to study either as it doesn't seem to be sticking in my head.

So i would love some tips to understand how to study chemistry better and more importantly enjoy studying it and studying it effectively so i truly understand it.

Thanks a lot.

I’ll write the desired and given info, but after that I seriously cannot figure out how to start any of the conversions and it’s very frustrating:(

I’m so confused the green is what I was trying to find but I can’t find any help videos and the textbook is confusing

Hi all, I’m testing a few approaches for a glucode oxidase-based electrochemical biosensors. Right now I’m starting with FcCOOH–GOx conjugation using EDC/NHS, before moving on to a cysteamine based approach.

I’ll test this on both gold and graphite/carbon electrodes.

My plan is;
Final concentrations:
• MES: 50 mM, pH 6

• EDC: **50 mM**

• NHS: **10 mM**

• GOx: **15 mg/mL**

• FcCOOH: 1 mM or 10 mM 

Protocol:
1. Dissolve FcCOOH in water or MES

2.  Prepare EDC and NHS separately (fresh)

3.  Mix FcCOOH + EDC + NHS and vortex/mix for **20 min**

4.  Run the electrochemical experiment

Control: FcCOOH + EDC + NHS
Sample: FcCOOH + EDC + NHS + GOx
For the sample, I was planning to add GOx, wait about 30 seconds, and immediately start the measurement
My main questions are:
• Does 50 mM EDC / 10 mM NHS sound reasonable?

• Is **20 min** enough for FcCOOH activation?

• Should I vortex or just mix gently?

• Is **30 sec after adding GOx** way too short?

• Would you change/add any controls?

• For FcCOOH, would you dissolve it directly in MES or prepare it separately first?

At this stage I just want to see whether adding/conjugating GOx produces a clear electrochemical change 
Any advice from people who have worked with FcCOOH, GOx, EDC/NHS coupling, or electrochemical biosensorswould be really appreciated🙏

If I want the other configuration which stereocenter do I need to change on the catalyst?

I just started my first semester at college and i'm currently in a gen chem 1 class with support. I'm aware chem is difficult and many people need to get help, but is it normal for the class work to have nothing to do with the homework? I have homework through pearson with a textbook linked and the textbook doesnt even have any information on the problem. Is this normal?

I know this is wrong but I dont know what im doing wrong. Can someone please help me

I've failed chemistry ever year ever since highschool. Now I'm in college and i still can't wrap my head around it and it's making me mad and irritated but I want to know how to do it and I'm just so tired of failing chemistry I've failed chemistry over 9 times in my life time im so mad

College level gen chem

I can pick out what the problem gives me but my brain blanks on where to go next. I've asked my professor and she told me what I need to do next - use d=m/v to get the volume then use M1V1=M2V2 but I dont understand how you know you need to do that.

I need to be able to know why for a full understanding. I've included my work before talking to my professor here, so I know the bottom conversion is wrong, I just havent finished it yet.

My brain when I first went through this problem was this -->

okay what is the problem giving me? great

what else can I get from this info? great

....okay now what do i do with this information?

I need an amount of solution...so i need to find mL? L? mass??

Please if someone can explain how you know you need to use M1V1=M2V2?

Did I even need to convert to moles HCl?

I have never encountered this type of tautomerisation/rearrangement before. If anyone can provide the arrow mechanism for it, I would be forever grateful.

My teacher didn’t explain very well on line bond structures and skips around a lot. For our homework she will give us either a molecular model of…lets say hexane or “write out the chemical formula for hexane” only and say “draw/convert into line bonds structure”. I tend to make everything into a lewis structures first then work from there but Im wondering if maybe there is a different way to approach these?

I don’t understand why this is easy for everyone, I really don’t know how to draw it, this is basic chemistry!

2.- How many joules are released when 45g of water at 0C is converted to ice at 0C

HOW DO I DRAW THAT I DON’T UNDERSTAND AND NO ONE IS EXPLAINING THIS TO ME!!!

Can please someone tell me how to do those equivalence , equivalence mass and percentage purity questions like I have done all of physical chemistry but I just can't solve those questions 😭

To be hetrocyclic the conditions are:

- A close ring

- An atom other than Carbon Or Hydrogen in the PC

Right?

GCSE student going into A level this year. I was doing summer work and found some cool things to research like liquid ions and crystalline solids vs amorphous solids. I was wondering if anyone had any suggestions for topics I could research for fun?

A lot of the other ones I’ve found online so far either have a lot of terms I don’t understand yet, or lean more into biology than chemistry. It’ll be great to hear a few ideas!

Thanks!

i'd say i have an average understanding of what it is...like i know it's a hybrid of orbitals like sp3, sp2, etc. but can someone explain it in full detail? my chemistry teacher teaches very fast-paced and i feel like im missing something.

i guess i just dont really understand how the electrons are filled in the hybrid orbitals and also how an sp2 orbital works.

could someone please help? thank you!!