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Subhomoy Bakshi
·2010-11-22 10:14:13
LOL!!! thats the most hilarious mistake i ever made!! LOL
C≡H
LOL!!
just LOL!! :P
11
Khyati
·2010-11-23 07:51:34
Vivek, most of Bhagwano ne isano ke roop mein hi iss sansar mein avtaar liya hai. [3][1]
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Vivek @ Born this Way
·2010-11-23 00:24:42
Hm.. Mera yaha kuch na kehta hi accha hoga..
@Pritish.
Aap Insan ke roop mein Bhagwan hai. Main toh kehta ho aap purush hi nai (Mahapurush hai)
Nice.!
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Khyati
·2010-11-22 12:07:39
Subhomoy, I think you need some rest to rejuvenate yourself because I fill you are too stressed about JEE .
I advice you take some rest and then start again with new fresh mind or may be you may make this kinda silly mistakes in ur exams and there you wont be able to laugh or cry.[3]
Just a advice, dont be offended or angry.
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Khyati
·2010-11-22 12:01:26
Now am giving a big and flawless explanation to why sp is more acidic than sp3
Ethyne is sp hybridised and its pka value is less than ethane's (sp3),hence its more acidic. This is bcoz of the relative stability of the unshared electrons in the conjugate bases of each of these compounds.
An s orbital has lower energy level than p orbital,therefore, d energy of the hybrid orbital decreases with the increase in s character, and its in order sp3 > sp2 > sp.
The unshared pair of electrons of conjugate base in ethane occupies sp3 orbital, which are in higher energy state than the unshared pair of electrons of ethyne which occupy the sp orbital. So the unshared pair of electrons of conjugate base in the sp orbital of ethyne are at lower energy state and hence are more stable. Thus the conjugate base of ethyne is weaker than the conjugate base of ethane or we can say that ethyne is stronger acid than ethane.
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Khyati
·2010-11-22 11:47:06
OMG, even I missed that. And was confused because of you Subhomoy. [3][4]
1
souradeepmajumde majumder
·2010-11-22 11:02:10
sp is more acidicthan sp3.......... increasing in s character increases the acidicity
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Subhomoy Bakshi
·2010-11-22 10:24:18
i am still laughing at myself!! :P
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Khyati
·2010-11-22 06:53:48
sp is mre acidic form because more the s character more is the acidity.
The sp hybrid orbitals have greater s character than sp2 and sp3, which allows
negative charge to be held closer to the nucleus upon protonation, lowering the
overall energy, and increasing the acidic character
for eg, ethyne(sp hybridised) is more acidic than ethane(sp3 hybridised)
Am confused here [3]
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Pritish Chakraborty
·2010-11-22 10:07:53
....
Of course ethyne is more acidic than ethane. Have you forgotten how the ethynide anion is used in nucleophilic substitutions, Subho? The anion is stable -> the original substrate is acidic. :\
The pKa of ethyne is 25 and that of ethane is 50...
Since when did ethyne have a C≡H bond??? It's H-C≡C-H!!
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Khyati
·2010-11-22 07:40:37
Neither I do with yours [3]
i do not agree with your statement :
for eg, ethyne(sp hybridised) is more acidic than ethane(sp3 hybridised)
i think te reverse is quite true!!
I need to revise and then will tell u.
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Subhomoy Bakshi
·2010-11-22 07:21:49
i do not agree with your statement :
for eg, ethyne(sp hybridised) is more acidic than ethane(sp3 hybridised)
i think te reverse is quite true!!
but i agre with :
sp is more acidic than sp3 because sp has more s character in it.
11
Khyati
·2010-11-22 07:16:59
Not very sure [3], but one thing I know is that sp is more acidic than sp3 because sp has more s character in it.
And since in ethyne there are 3 bonds to be broken we need more energy to break the bonds than ethane where only one bond i to be broken.
I think I should not explain that in terms of examples.
So the final answer,
sp is mre acidic form because more the s character more is the acidity.
so sp is more acidic than sp3
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Subhomoy Bakshi
·2010-11-22 07:12:59
@ Khyati: are u sure??
because the to break away the C≡H in ethyne it will always require more energy than breaking away the C-H bond in ethane..(why?)
in such cases isn't ur answer contradicting your logic???
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Subhomoy Bakshi
·2010-11-22 07:02:11
if all other conditions are uniform for 2 species except hybridisation, then the sp hybridised species is more acidic!!