« first day (1754 days earlier)      last day (2636 days later) » 

Thanks
don't really want to bother though; think I've said enough
 
Jan
I’m kinda like … If this is not a question about the Lewis structure for iodate, what is the question about? Proving to my teacher that they are wrong? If yes, please ask somewhere else.
 
Yup, that's how I interpret it.
@gannex There's an issue with simply saying SET, in that the reduction of OX- to X- is a 2-electron process, whereas the oxidation of the radical to the nitrosonium cation is a 1-electron process.
By SET I mean something like in Marcus theory: $\ce{D + A -> D+ + A-}$
which is why I don't know haha
 
I agree. That's why I'm having trouble with the mechanism.
 
hope you get an answer.
 
12:27 AM
me too
I highly doubt my prof cares if I know this though :P
 
But that's the best kind of question, those that you don't need to know the answer to. ;)
2
 
OK, so at least it's non-obvious, eh
yeah. I'm always worried about things like
"where EXACTLY is the electron?"
 
12:41 AM
@DSVA thanks for sharing.
 
 
2 hours later…
3:04 AM
Can anybody explain me what would be the product in this reaction
 
3:46 AM
Help are you prep for iit
 
Yes
 
 
2 hours later…
5:28 AM
So let's help together in this way of success
 
 
2 hours later…
7:23 AM
@satyatech so please help me in this
 
KMnO4 oxidizes the alkenes
@help
 
@anonymous so how many CO2 molecules will be produced
 
@help Try yourself. I told you the method. Even the double bonds in the ring will be oxidized
 
@anonymous does for every double bond there would be 1 CO2 molecule
 
@help No
 
7:31 AM
Then
 
Only for terminal alkenes CO2 is produced
 
So in this case there is only one terminal alkenes
 
yep
 
There would be only one molecule of CO2
 
yes
 
7:33 AM
But the answer given as 4
4 moles of CO2 per mole of compoud M in the above reaction
 
Yes, even if formic acid is produced that too will be oxidized to CO2
CO2 is simply H2CO3 in aqeous medium
See the rule I told you above
 
@anonymous and from where formic acid would be produced
 
However I can't see how 4 CO2 can be formed
Probably your book is wrong
 
@anonymous sorry , but first I want to know concept behind it
 
Which book do you use ?
 
7:38 AM
This question came in my test paper
 
@help Can I see the whole question ?
Okay I got it
See O should be inserted between ALL C-H bonds too
Remember?
Try now
 
@anonymous yes
 
Sorry, even if O is inserted between C-H even then all the C-C bonds can't break.
4CO2 means some C-C bonds are broken
And that is not possible
I think you should ask on the main site
 
I had asked , but it is puton hold
 
Hmm, I saw. Maybe you should ask you teacher. According to me the answer is wrong. See the mechanism here (youtube.com/watch?v=_lB3HcdPNGM)
 
7:51 AM
Ok
 
If you come to know why 4 is the correct answer do let me know
I will try to ask my teacher too
Good luck
 
Yeah
 
 
2 hours later…
10:16 AM
1
Q: Law of mass action & Collision Theory

MockingbirdI don't understand why the stoichiometric coeffcients of reactants and products are expotentialized in law of mass action. So I checked on wikipedia. And this popped out: In the 1879 paper[9] the assumption that reaction rate was proportional to the product of concentrations was justified mi...

 
 
2 hours later…
11:57 AM
> Tween 80 (a polyethylene sorbitan fatty acid ester)
What could this mean, the phrase in the brackets?
 
Polysorbate 80 is a nonionic surfactant and emulsifier often used in foods and cosmetics. This synthetic compound is a viscous, water-soluble yellow liquid. == Chemistry == Polysorbate 80 is derived from polyethoxylated sorbitan and oleic acid. The hydrophilic groups in this compound are polyethers also known as polyoxyethylene groups, which are polymers of ethylene oxide. In the nomenclature of polysorbates, the numeric designation following polysorbate refers to the lipophilic group, in this case the oleic acid (see polysorbate for more detail). The full chemical names for polysorbate 80 are...
 
polyethoxylated sorbitan - so it must have a lot of ethylene oxids upon it?
But I can't see ethylene oxids on it
 
12:13 PM
@CowperKettle No, it's got repeat $\ce{-OCH2CH2 -}$ groups. The ring opens when one forms polyethoxy things.
 
Polyethylene glycol (PEG) is a polyether compound with many applications from industrial manufacturing to medicine. PEG is also known as polyethylene oxide (PEO) or polyoxyethylene (POE), depending on its molecular weight. The structure of PEG is commonly expressed as H−(O−CH2−CH2)n−OH. == Available forms and nomenclature == PEG, PEO, and POE refer to an oligomer or polymer of ethylene oxide. The three names are chemically synonymous, but historically PEG is preferred in the biomedical field, whereas PEO is more prevalent in the field of polymer chemistry. Because different applications require...
 
Totally unrelated: what is a good example of a metal complex that has purely (or nearly) $\sigma$ backbonding, and what is one that has purely (or nearly) $\pi$ backbonding?
 
Hii @CowperKettle
 
It's too early in the morning for me to try to make sense of Wikipedia's writeup
 
@Loong sorbitan has PEG groups upon it?
Is sorbitan an alcohol?
 
12:19 PM
@CowperKettle yes
Sorbitan is a mixture of isomeric organic compounds derived from the dehydration of sorbitol and is an intermediate in the conversion of sorbitol to isosorbide. Sorbitan is primarily used in the production of surfactants such as polysorbates; which are important emulsifying agents, with a total annual demand of more than 10000 tons in 2012. == Synthesis == Sorbitan is produced by the dehydration of sorbitol and is an intermediate in the conversion of sorbitol to isosorbide. The dehydration reaction usually produces sorbitan as a mixture of five- and six-membered cyclic ethers (1,4-anhydrosorbitol...
 
> Alcohol ethoxylates and ethoxysulfates are surfactants, used widely in cosmetic and other commercial products.
But in our case it's not an alcohol?
Is any chemical that has -OH groups an alcohol?
 
Oy.
<facepalm>
Never mind, misread.
I didn't think there was any such thing as $\sigma$-backbonding, and I was right.
 
> In chemistry, an alcohol is any organic compound in which the hydroxyl functional group (–OH) is bound to a saturated carbon atom.
Sorbitan must be an alcohol.
It has four OH groups attached to saturated C's
So, basically, sorbitan gets polyethoxylated, and this polyethoxylated sorbitan forms an ester with oleic acid?
 
@CowperKettle yes
 
Phew. And sorbitan is an alcohol, only it does not have the ol suffix.
 
 
2 hours later…
2:16 PM
Well, glucose is an alcohol too. ;)
And propofol isn't an alcohol.
Neither is ortho-cresol.
 
2:49 PM
There's nothing to review. Somebody kick me off this site.
 
@M.A.R. ok
Why do we get so many questions with turned pictures? Is it really so difficult to upload a proper picture? Any simple image software can rotate a picture.
 
3:06 PM
@Loong They care for you and want you to exercise your neck a little bit
In this era of machinery all Loongs need neck exercise.
Title of the day
-4
Q: Want this feature

Saumya Brata DuttI couldn't find the comment button or a way to comment on a post, just had an option to Answer. Any help or you might need to add that feature. Thanks

Hmm, @Loong wasn't there a tag specifically for proton NMR?
 
3:23 PM
I only know .
I guess most questions are about 1H NMR.
 
Mhm
 
 
2 hours later…
5:01 PM
@orthocresol Thank you! I just haven't had time to sustain my chemical knowledge. I last studied chemistry in June 2016
 
5:12 PM
@Loong can you please help me in this
 
You need to know the product of the reaction?
 
@CowperKettle i don't know that only
 
Seems I beat Phil Baran by 23 minutes. ;D
 
5:28 PM
Why this chat room is so dead .
 
5:51 PM
@hBy2Py I see how the big red box makes it more obvious, but I really don't see how it's unclear what I'm asking for. The wording of the question makes it clear.
 
6:03 PM
@help I'm here
@orthocresol I would've been down to ask some questions, but r/science always bans me.
 
@gannex Make a throwaway haha
 
I need to keep it out of my regular frontpage, otherwise I just respond to science threads like they were regular threads.
meh
the AMA question period is over, isn't it?
 
I don't know, he's still answering questions.
You could try.
 
@gannex Well, maybe I was being particularly dense, but I wasn't sure if you were asking about a subset of the mechanism, or about the entire mechanism.
 
it's alright. I've got to study anyways. I'll go check what you asked though, @orthocresol
 
6:13 PM
I didn't ask anything, actually
 
@hBy2Py I can see how it would be confusing the way I initially worded my question, but I changed the wording to clarify. I guess the box makes it pretty obvious though
 
@help Because most of the regular chatters aren't from North/South America, and are asleep or otherwise away from their computers around now.
 
"the exact process by which TEMPO is oxidized to the nitrosonium cation by NaOCl, as in subset of the mechanism shown in the diagram." clearly shows that I'm asking about the part of the mechanism you put in the box
 
It's always pretty dead through the afternoon of Eastern Standard
 
I'm awake 24 hours a day though
better living through chemistry.
 
6:15 PM
@gannex I didn't see any updates to the question until you pinged me in your comment.
The question was already closed by the time I woke up this morning.
 
Ah OK. I changed the wording before the picture was edited
I am lazy with editing images.
 
If I'd seen your edit before the question closed, I probably would've retracted my close vote.
 
anyways, it's alright. I'm going to do some reading and see if I can answer it myself.
 
I've already voted to reopen.
 
thx :-)
 
6:16 PM
I have a handwave idea as to the answer, but nothing concrete.
Part of the problem is that the TEMPO oxidation is a one-electron step, AFAIK.
So I think the stoichiometry is funny, and/or there's a concerted oxidation of multiple TEMPOs
 
the confusion is that TEMPO oxidation is 1 electron, but you need to get a Cl- from the OCl-, which means there's a two electron arrow somewhere in there.
 
<nod>
 
oh. Actually, the picture I used may be unclear there. The stoichiometry I have seen in other books shows TEMPO + 1/2 NAOCl -> nitrosonium chloride
 
Explicitly adding that detail to the question (1e- vs 2e-) may further your cause.
 
but that doesn't make sense because there's a whole chloride ion in nitrosonium chloride... and where does the oxygen go?
OK I'll go edit it when I'm done my studying
 
6:19 PM
Oh, I think it's a great question -- I now wish my initial confusion hadn't started the process of getting it closed.
 
who can open it?
 
@gannex done
 
@Loong thanks
 
@gannex so could you help me in that
@hBy2Py oh I see
@hBy2Py so at which time it is highly active
 
6:35 PM
@help UTC+0:00
what was the question?
 
 
ohh this
 
@gannex in this how much CO2 molecule would be the product
@gannex yeah
 
do you know what the conditions are?
water, acid, base?
 
No
The answer is given as 4
 
6:38 PM
you only get CO2 at the positions where your unsaturated carbon has no other R groups
look for =CH2
but the question is abd
bad
 
So there is only one such group
 
because this sort of thing only occurs in concentrated acidic potassium permanganate
manganese oxidation is anoying because there are three different KMnO4 reductions, depending on the pH of the solution... hang on lemme get a picture
 
chemistry.stackexchange.com/questions/68321/… in this max has said the product would be pentanedioic acid
 
not sure how you get glutaric acid
 
Ohk
 
6:47 PM
unless there's a rearrangement, it seems like you would get propanedioic acid, another thing, and CO2, and H2O
either way, there's only 1 =CH2 group, so you can only get 1 CO2
everything's different if there's some rearrangement though
why don't you follow the chemguide link and see what products you can predict?
 
Don't know I am weak in organic
 
(assuming they mean concentrated acidic KMnO4)
well just look at the disconnections for C=C's with different substitutions and put transfer those ideas to your molecule
 
@gannex I got 3 molecules of CO2
One from =CH2
And the ring also breaks into 2 molecules of 1,3di carboxylic acid
Which on heating produces co2
 
if decomposition of malonic acid occurs via the regular β-keto decarboxylation pathway, you only get one mole of CO2
but I didn't even think of that
tricky question actually.
so it looks like your products would be AcOH, CO2, H2O, CO2, and AcCH(CO2H)2
does that make sense?
 
7:03 PM
Yes ,I think so
@gannex and one from =CH2
 
7:18 PM
yes, so 2CO2
unless the 6-membered ring part of the molecule further rearranges somehow
actually
yeah
if you can get thermal β-keto decarboxyllation-type decomposition of malonic acid, AcCH(CO2H)2 will also decomposition, since it's also a malonic acid.
 
@gannex from that how much CO2 would be produced
 
well first you'll get a β-keto decarboxyllation with one of the CO2H's and the Ac (COCH3) group, so that's one CO2, but then you get another β-ketone, so you'll get a second decarboxyllation, finally yielding acetone and 2 CO2
so you get 4 CO2
 
Ohh finally got it
 
now our products would be AcOH CO2, H2O, CO2, CO2, CO2, and CH3COCH3
 
Thanks @gannex
 
7:24 PM
if we assumew that β-keto decarboxyllations will just keep happening
If you want I'll write up a scheme when I'm done my studying, and answer your question.
 
@gannex ok when you are free
Thanks
 
but as I said the question is bad because it doesn't actually state that it's concentrated acidic KMnO4
 
Yeah
 
is the question from a textbook or a class?
also, we'd have to know the temperature and stuff to be sure about those thermal decarboxyllations, because it probably depends on the exact stability of the different malonic acids.
 
This came in a test paper
 
7:32 PM
anywas, i think the question was phrased badly, but it seems like they're trying to get you thinking about β-decarboxyllation
oooh
4 was the answer!
yay
OK I'll write up a scheme now.
 
8:04 PM
@Jan I just wrote up a scheme for help's question and I'd like to post an answer.
I don't want to waste 15 minutes chemdrawing >:-( , but I guess help's question was homework, so what should I do?
 
8:38 PM
welp, @help; here's your scheme
 
 
1 hour later…
Jan
10:00 PM
@gannex Why did you ping me of all people? *confused*
 

« first day (1754 days earlier)      last day (2636 days later) »