acidic H

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xoangelxo

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Which hydrogen is the most acidic next to a carbonyl? Would it just be the alpha carbon is the most acidic, then the beta...etc? :confused:
Like in this question, what is the most acidic H?
H3C-C=O-CH2-CH2-CH3
Orange or blue and why?..thanks

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anyone else??.. so do carbcations and carbanions follow the same stability rule then...meth < prim < sec < tert?
 
Yes, agree with everyone!

Just remember that if it is a terminal alkene or alkyne than the terminal H is more acidic!
 
corrected...:rolleyes:

carbanion stability:

meth < prim < sec < tetr

sorry everyone...once again laundry is WRONG again.

look it up

page 407 organic chemistry 4th edition paula bruice

most STABLE is

meth > primary > second > tert

once again you're stupid...look up your facts before you post
 
Ok, Pchemgrad and Laundry are wrong!

I'm not sure...but maybe you're confusing it w/ carbocation. The exact opposite is true for a carbanion.

By the way...resonance has nothing to do w/ the question. So, let's get that straight.

If the carbons are electron donating, this explains why a carbocation (plus) charge is stabilized. Ok, that was basic...we all know that.

So, does the same electron donating effect stabilize a negative charge???

Obviously not!

Here is something to think about:

The pKa of methanol is 15.5 while the pka of ethanol is 15.9....why do you suppose this is true? Furthermore, isopropyl alcohol has a pka of 16.5. Again...notice a pattern?

Back to the problem...C2 is going to be less acidic b/c the subsequent carbanion is destabilized by the inductive effect...the environment of C2 is more electron donating. This can easily be examined by looking at the respective carbanions generated by removing a proton at both C1 and C2 respectively.
 
sorry everyone...once again laundry is WRONG again.

look it up

page 407 organic chemistry 4th edition paula bruice

most STABLE is

meth > primary > second > tert

once again you're stupid...look up your facts before you post

You need to chill the hell out and stop calling people names, that is absolutely ******ed. That being said, i wasnt sure on this b/c i havent brushed up on it lately but i know carbocations are tert>sec>ect..... I grabbed my old o-chem book from back in the day....while I couldn't find anion stability directly, i did quickly come across a table of acid strengths and noticed that the Ka of ethane CH3CH2-H is higher (higher = more acidic) than that of 2-methylpropane (CH3)3C-H. This would support the carbanion stability trend opposite that of carbocations since the ethane hydrogen being lost is on a primary carbon and the hydrogen being lost on the 2-methylpropane is on a tert. carbon. I cant exactly remember the reason carbanion and carbocation stabilies are opposite but i think i recall something about the positive charge of a carbocation being stabilized by surrounding electron density (in this case more carbons) and the carbanion being destabilized by surrounding electron density b/c it already has a negative charge (like charges repel). Dont quote me on my reasoning here, but do quote me on this: jdsamarui, if your going to call people names like a 5 yr old then you shouldnt be posting at all...and if you are going to act like your Mr. Chemistry then at least go ahead and explain things to those who dont know. Dont just come in, say ur dumb, and leave....O-chem principles are always easier to remember when you understand the chemical reasoning behind the behavior you are discussing. I took the DAT a while ago and missed 2 questions on the o-chem part, so keep studying people and good luck.:cool:
 
You need to chill the hell out and stop calling people names, that is absolutely ******ed. That being said, i wasnt sure on this b/c i havent brushed up on it lately but i know carbocations are tert>sec>ect..... I grabbed my old o-chem book from back in the day....while I couldn't find anion stability directly, i did quickly come across a table of acid strengths and noticed that the Ka of ethane CH3CH2-H is higher (higher = more acidic) than that of 2-methylpropane (CH3)3C-H. This would support the carbanion stability trend opposite that of carbocations since the ethane hydrogen being lost is on a primary carbon and the hydrogen being lost on the 2-methylpropane is on a tert. carbon. I cant exactly remember the reason carbanion and carbocation stabilies are opposite but i think i recall something about the positive charge of a carbocation being stabilized by surrounding electron density (in this case more carbons) and the carbanion being destabilized by surrounding electron density b/c it already has a negative charge (like charges repel). Dont quote me on my reasoning here, but do quote me on this: jdsamarui, if your going to call people names like a 5 yr old then you shouldnt be posting at all...and if you are going to act like your Mr. Chemistry then at least go ahead and explain things to those who dont know. Dont just come in, say ur dumb, and leave....O-chem principles are always easier to remember when you understand the chemical reasoning behind the behavior you are discussing. I took the DAT a while ago and missed 2 questions on the o-chem part, so keep studying people and good luck.:cool:

you my friend, are an idiot. you don't even know what's going on. i have been explaining and answering everyone's question here in the DAT forum. but Mr. Laundry here keeps coming in trying to correct me with a certain sarcasm. Before I answer any questions I usually look it up to make sure I'm right. You know the saying goes "stupid people spread stupidity." so before you try to correct someone look up the facts and correct them.
 
you my friend, are an idiot. you don't even know what's going on. i have been explaining and answering everyone's question here in the DAT forum. but Mr. Laundry here keeps coming in trying to correct me with a certain sarcasm. Before I answer any questions I usually look it up to make sure I'm right. You know the saying goes "stupid people spread stupidity." so before you try to correct someone look up the facts and correct them.

lmao, u sound awesome. U are still calling people names. wth is wrong with you? I dont care what the history is b/w u 2, it doesnt make it alright for you to call people names like a child. If your tired of whoever is annoying you then just stop reading their posts, and if necessary, stop visiting this forum. U cant even be polite to someone on a forum that you dont even really know, that is not good. Good luck Mr. Personality :cool: Oh, and btw, i'm sure as hell not your friend.
 
so the whole ordeal you are trying to defend someone who posts up wrong answers?...um ok....reading their posts?...lol...don't you see they are trying to correct me...but whatever....why dont you go shag something sirshagalot
 
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