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Author: Subject: Did anyone can find me the pKa of these bases salts
dextro88
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[*] posted on 10-6-2020 at 07:18
Did anyone can find me the pKa of these bases salts


For a little experiment i need to know exactly whats the pKa of :
methylamine acetate
ethylamine acetate

and will be very thanksfull if anyone can show me how i can calculate the pKa of various bases salts.

best regards :)



[Edited on 10-6-2020 by dextro88]
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Tsjerk
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[*] posted on 10-6-2020 at 07:43


These compounds are not acids, they are neutral salts, so they don't have a pka.

(M)ethylamine has a pKb and acetic acid has a pka.
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dextro88
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[*] posted on 10-6-2020 at 08:24


thanks for the lesson, i need to know wich one is more acidic, i know most of the bases salts have a pKa by wich they get neutralized and are liberatet from acidic ions,amonium acetate have pKa of 9.9, but i dont understand why its not the same here.

many thanks, dextro :)



[Edited on 10-6-2020 by dextro88]
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[*] posted on 10-6-2020 at 09:24


Well, methylammonium ion has a pKa of 10.6 and ethylammonium ion 10.8
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dextro88
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[*] posted on 10-6-2020 at 10:12


yes thats already accesible information, but i want to learn the calculation behind how to calculate the pKa of these various salts, for example anhydrous amonia have a pKa of 37 and in presence of water much lower and acetic acid have pKa of 4.76, how the amonium acetate pKa is calculated 9.9 i just cant understand the math behind that.



[Edited on 10-6-2020 by dextro88]
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[*] posted on 10-6-2020 at 11:42


Have a look at the answer given by Bive:

https://chemistry.stackexchange.com/questions/75047/ph-of-am...
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dextro88
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[*] posted on 11-6-2020 at 07:34


thank you for your effort, im still newbee its a litle hard calculations for me, but i will work my way to understand and do these calculations myself.

Best regards :)

[Edited on 11-6-2020 by dextro88]
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