Sciencemadness Discussion Board

Did anyone can find me the pKa of these bases salts

dextro88 - 10-6-2020 at 07:18

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]

Tsjerk - 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.

dextro88 - 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]

Tsjerk - 10-6-2020 at 09:24

Well, methylammonium ion has a pKa of 10.6 and ethylammonium ion 10.8

dextro88 - 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]

Tsjerk - 10-6-2020 at 11:42

Have a look at the answer given by Bive:

dextro88 - 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]