View Full Version : conjugate acid question


Dentist2be
08-17-2005, 07:26 PM
H2C2O4(aq) +H2O(l) <--> HC2O4-(aq) + H3O+(aq)

The answer key says H3O+ is the only conjugate acid. Why can't H2C2O4 be a conjugate acid as well?? (it also donates a proton..)

Thank you for your help!

chordata
08-17-2005, 07:53 PM
conjugate acids and bases only show up on the products side and are paired with their corresponding acid/base on the reactant side.

joonkimdds
08-17-2005, 08:04 PM
H2C2O4(aq) +H2O(l) <--> HC2O4-(aq) + H3O+(aq)

The answer key says H3O+ is the only conjugate acid. Why can't H2C2O4 be a conjugate acid as well?? (it also donates a proton..)

Thank you for your help!

The acid(or base) on the left becomes its conjugate base(or conjugate acid) on the right.

Acid + Base <==> Conjugate Base + Conjugate Acid

and uh...i also wanna know...if 1 = x , then why can't we put it x = 1 ?

GCT
08-17-2005, 09:46 PM
H2C2O4(aq) +H2O(l) <--> HC2O4-(aq) + H3O+(aq)

The answer key says H3O+ is the only conjugate acid. Why can't H2C2O4 be a conjugate acid as well?? (it also donates a proton..)

Thank you for your help!

any arrehnius acid base reaction will consist of the weaker conjugate acid/base pair and stronger conjugate acid/base.

where on earth are you getting all this from?

Dentist2be
08-18-2005, 02:46 AM
any arrehnius acid base reaction will consist of the weaker conjugate acid/base pair and stronger conjugate acid/base.

where on earth are you getting all this from?


Here is another question.

Q. What are the conjugate bases in the following reaction?

H2SO4 + H2O --> HSO4- + H3O+

A. H2O and HSO4-

The previous question is from Barron's and this one is from the website above.. getting more confused :confused:

GCT
08-18-2005, 11:35 AM
Which two compounds in the reaction act as arrehnius bases? Water acts as a base in the forward reaction right, it's protonated. The reverse reaction, although, it does not occur appreciably is where HS04- deprpotaontes hydronium. The stronger base is obviously water, since the forward reaction occurs, almost to completion.

Dentist2be
08-18-2005, 02:31 PM
My question was, why the first reaction [H2C2O4(aq) +H2O(l) <--> HC2O4-(aq) + H3O+(aq)] has only one conjugate acid, H3O+, whereas the second reaction [H2SO4 + H2O --> HSO4- + H3O+] has two conjugate bases (H2O and HSO4-).. maybe it's something to do with the direction?? i don't know..

GCT
08-19-2005, 11:04 AM
Now think about this, observe your first reaction

It it were so that the reaction has a conjugate acid, than this would mean that there exists its corresponding conjugate base, this base is the deprotonated form of the acid. Now this conjugate acid, is an "acid" because it has reacted with a base in an arrehnius fashion. Therefore the latter base also has a conjugate acid. There are two conjugate acids and two conjugate bases in every acid base reaction.

One can make a subtle case though, that the second reaction with sulfuric acid has only one conjugate base, H20, (thus one conjugate acid) since the reverse reaction with HS04- does not occur appreciably.

If this doesn't make sense to you, you'll need to read your text, it's pretty basic stuff.