Textbook clarification: weak acids and bases

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DHavo_1E
Posts: 118
Joined: Sat Aug 17, 2019 12:17 am

Textbook clarification: weak acids and bases

Postby DHavo_1E » Thu Jan 16, 2020 11:01 pm

Hello,

Could someone explain what the textbook means when it says that a solution of a weak acid in water would have a very, very low concentration of OH- ions to maintain autoprotolysis equilibrium? Thank you!

AArmellini_1I
Posts: 107
Joined: Fri Aug 09, 2019 12:15 am

Re: Textbook clarification: weak acids and bases

Postby AArmellini_1I » Thu Jan 16, 2020 11:07 pm

So because it is a very weak acid/base it only dissociates by a small concentration. Therefore, since your KA or B is [products] / [reactants] and only a small concentration will dissociate into the product, Ka or B is a very small number divided by a much bigger number which = a very small number :) So to add on, you only need a small concentration of OH- ions to maintain equilibrium.

DHavo_1E
Posts: 118
Joined: Sat Aug 17, 2019 12:17 am

Re: Textbook clarification: weak acids and bases

Postby DHavo_1E » Sun Jan 19, 2020 9:42 pm

AArmellini_1I wrote:So because it is a very weak acid/base it only dissociates by a small concentration. Therefore, since your KA or B is [products] / [reactants] and only a small concentration will dissociate into the product, Ka or B is a very small number divided by a much bigger number which = a very small number :) So to add on, you only need a small concentration of OH- ions to maintain equilibrium.



Hi,
This helped me understand a lot more thank you! Also, are the OH- ions the conjugate bases of water? Thank you!!

Rafsan Rana 1A
Posts: 55
Joined: Sat Aug 24, 2019 12:16 am

Re: Textbook clarification: weak acids and bases

Postby Rafsan Rana 1A » Sun Jan 19, 2020 10:23 pm

OH- are the conjugate base of water. However, if water reacts with an acid, wouldn't it act as a base thus it would have a conjugate acid of hydronium ions?


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