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DLS
 3 years ago
How do I find Pka for organic compounds?
DLS
 3 years ago
How do I find Pka for organic compounds?

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Preetha
 3 years ago
Best ResponseYou've already chosen the best response.1Look in the table of pKas.

abb0t
 3 years ago
Best ResponseYou've already chosen the best response.2Yes @Preetha is right. You can find them online or in your textbook, but if you need or want specific ones, i can give you a table once I make it of the common pKa's that I used in my organic class that helped me in class and on the ACS exam for organic chemistry.

DLS
 3 years ago
Best ResponseYou've already chosen the best response.0dw:1359698826745:dw lol not so precise hope u get it.. i have to answer which of the foll will have lowest Pka values..how do i do that? @abb0t @Preetha

abb0t
 3 years ago
Best ResponseYou've already chosen the best response.2These are some values of some of the pKa's that I found to be most important and useful during my organic series. I highlighted the acids to help you notice which acids are strong and which ones are weak. I HIGHLY suggest that you memorize the pKa of water as it is commonly used in ochem often and just knowing it's pKa will help you determine where the reaction lies, and whether it would be appropriate to do a reaction and so forth.

abb0t
 3 years ago
Best ResponseYou've already chosen the best response.2I also highlighted a carboxilic acid. I think you might get into that one in the last part of organic, but it helps to know it as you end ochem 1 with alcohols, gringards, and oxidative reactions. Best of luck!

abb0t
 3 years ago
Best ResponseYou've already chosen the best response.2As far as your question, the way I look at is is resonance. Secondly, you want to see if there are more carbons. If you notice on the pKa table that I attached, carbons tend to have more basic pKa values. Secondly, I would notice the resonance. Benzenes are pretty darn stable molecules. It has complete resonance around it's whole structure. This makes the structure more stable, loweing its potential energy. Less likely to want to want to react due to it's stability.

DLS
 3 years ago
Best ResponseYou've already chosen the best response.0So what is the Pka of benzene?

DLS
 3 years ago
Best ResponseYou've already chosen the best response.0more no.'s of carbon= less Pka?

abb0t
 3 years ago
Best ResponseYou've already chosen the best response.2Since benzene is merely all carbons and hydrogens with high stability, I would assume its w/ in the same range as other carbons. If I remember correctly, benzene pKa = 43.

abb0t
 3 years ago
Best ResponseYou've already chosen the best response.2Yes. The more carbons, the more basic your molecule is.

DLS
 3 years ago
Best ResponseYou've already chosen the best response.0more no.'s of carbon= less Pka? can you go a little more detail in this perhaps? little confused..

abb0t
 3 years ago
Best ResponseYou've already chosen the best response.2No. Remember, the lower the pKa the more acidic it is. The higher the pKa the more basic it is. Compounds like NH2 and OH are highly basic.

abb0t
 3 years ago
Best ResponseYou've already chosen the best response.2You can base it off water ~ 15.7 (pH of about 7)

abb0t
 3 years ago
Best ResponseYou've already chosen the best response.2For instance: dw:1359709156170:dw Seeing as how NH2 is REEEEALLY high due to it's instability, the reaction, by just looking @ pKa's you know will proceed towards the product side. You have a 25 and a 38.

VincentLyon.Fr
 3 years ago
Best ResponseYou've already chosen the best response.0Usually it goes this way: If you have to compare the relative strength of acids, you need to compare the stability of their conjugate bases. Form the conjugate base of each of your acid, then look out for resonances. If their are resonances, the base is stable ie, easy to form, so the acid will lose easily its proton: stronger acid. If there are no resonances in the base, the acid is weaker.

abb0t
 3 years ago
Best ResponseYou've already chosen the best response.2Geebus, @VincentLyon.Fr you always write everything I mean to say in such a smooth manner. Lol. darn u for ur great flow with werds :P

VincentLyon.Fr
 3 years ago
Best ResponseYou've already chosen the best response.0Hehe! Privilege of old age and experience ;)
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