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Topic: which structure is more stable and which structure is more acidic,why?  (Read 3665 times)

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Offline merkel

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Obiviously, triethyl orthoformate is more acidic than ethnol.
But when both of them deprononated, the negative charge is on oxygen of triethyl orthoformate, while on carbon of ethnol.
     1.According to rules learned from organic chemistry, the negative charge on a more electronegative atom(eg. O) is more stable than on less electronegative atom(eg. C).
     2.According to rules that when the conjugate base is more stable, then the conjugate acid is more acidic.
So,we can conclude that  triethyl orthoformate is less acidic than ethnol.

Seemingly contradictory? I don't know where am I wrong.

« Last Edit: June 03, 2013, 12:52:26 AM by merkel »

Offline discodermolide

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When ethanol is deprotonated the negative charge resides on oxygen not carbon.
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Offline camptzak

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how do you know triethyl orthoformate is more acidic than ethanol?
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Offline merkel

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how do you know triethyl orthoformate is more acidic than ethanol?
Triethyl orthoformate is an orthoester of formic acid and ethanol. So generally it's more acidic than ethanol.

Offline camptzak

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 do you have some sort of reference table? or reference? I would say that ethanol is more acidic.


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Offline merkel

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do you have some sort of reference table? or reference? I would say that ethanol is more acidic.
I don't have one. I can't it by googling,too.

Offline camptzak

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I am pretty sure ethanol is more acidic. but if you don't believe me you could message a more senior forum member.

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Offline merkel

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I am pretty sure ethanol is more acidic. but if you don't believe me you could message a more senior forum member.
Can you tell me how do you reach your conclusion ? A senior forum? for example?

Offline Dan

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Quote
Obiviously, triethyl orthoformate is more acidic than ethnol.

This is not obvious - it is the opposite of what the "rules" predict. If you can't find data, you must at least have a logical reason for thinking triethyl orthoformate would be more acidic.... do you?

You have already explained why ethanol is more acidic, so I really can't understand why you find the reverse "obvious":

     1.According to rules learned from organic chemistry, the negative charge on a more electronegative atom(eg. O) is more stable than on less electronegative atom(eg. C).
   

I expect ethanol is substantially more acidic than triethyl orthoformate for that reason.
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Offline opsomath

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Orthoformate is hardly acidic at all. It has no acidic hydrogen.

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