How is Na+ the conjugate acid of the strong base NaOH? (1 Viewer)

[chocolatelatte]

So basically I'm really confused about the definitions of conjugates cus of that.

I understand that if
OH- + H3O+ -> H20 + OH-
the base/conjugate acid pair is OH-/H2O
the acid/conjugate base pair is H3O+ and OH-

BUUUUUUUT with NaOH
how does NaOH + H3O+ -> H2O + Na+ + OH-
how is Na+ the conjugate acid here....................................

thanks !!

 

[Librah]

So basically I'm really confused about the definitions of conjugates cus of that.

I understand that if
OH- + H3O+ -> H20 + OH-
the base/conjugate acid pair is OH-/H2O
the acid/conjugate base pair is H3O+ and OH-

BUUUUUUUT with NaOH
how does NaOH + H3O+ -> H2O + Na+ + OH-
how is Na+ the conjugate acid here....................................

thanks !!

Your equations don't make sense.

First one i'm assuming is supposed to be OH- + H30+ <--> H20 +H20
And your last equation, i dunno what that is, though either way, neither are balanced.

 

[chocolatelatte]

Whoops my bad!!!
hahahaha you're right- they aren't, and they are most certainly incorrect.
but my question still stands.

basically
if NaOH + HCl -> NaCl + H2O
What are the acid/conjugate base pairs and vice versa?

because in the textbooks, they give examples like
HCl + h20 -> Cl- + H3O+
where HCl and Cl- are the acid/ conjugate base pairs respectively, and i understand this, but i just can't seem to extrapolate this to eqns like the one with naoh and hcl....


btw, i ask this because when you're determining whether a salt is acidic or basic or neutral, sometimes you get salts like NaCl and their reasoning is that Na+ is the conjugate acid of a strong base (and therefore is not basic) , same for Cl-, but I understand why Cl- is the conjugate base of a strong acid, just not why Na+ is the conjugate acid of a strong base.

 

[Librah]

Whoops my bad!!!
hahahaha you're right- they aren't, and they are most certainly incorrect.
but my question still stands.

basically
if NaOH + HCl -> NaCl + H2O
What are the acid/conjugate base pairs and vice versa?

because in the textbooks, they give examples like
HCl + h20 -> Cl- + H3O+
where HCl and Cl- are the acid/ conjugate base pairs respectively, and i understand this, but i just can't seem to extrapolate this to eqns like the one with naoh and hcl....


btw, i ask this because when you're determining whether a salt is acidic or basic or neutral, sometimes you get salts like NaCl and their reasoning is that Na+ is the conjugate acid of a strong base (and therefore is not basic) , same for Cl-, but I understand why Cl- is the conjugate base of a strong acid, just not why Na+ is the conjugate acid of a strong base.

Technically Cl- is an extremely weak conjugate base here since it was formed when a strong acid donated a proton by BL theory (not entirely sure of this), and H20 is the conjugate acid as it was formed when a strong base accepted a proton. Neither Na+ or Cl- will undergo hydrolysis though, so you'll have a neutral solution. So in a way H2O is the only acid/base here, since it is the only thing that will undergo hydrolysis, and it will do this with itself. Na+ is simply a spectator ion , you might want to get a second opinion on this though, cause i was a bit iffy on this.

 

[Ekman]

The whole concept of conjugate acid or base pairs are based on Bronsted-Lowry's theory of acids and bases.

A conjugate Acid is a Base that has gained a proton:
HCl+H2O -> H3O+ + Cl- (H3O+ is the conjugate acid)

A conjugate Base is an Acid that has lost a proton:
HCl+H2O -> H3O+ + Cl- (Cl- is the conjugate base)

Now in terms of your question about NaOH
NaOH + HCl -> Na+ + H2O + Cl-
The conjugate is base is obviously the Cl-, and the conjugate acid is the base that has gained proton, thus it is the H2O.
For an easier understanding:

Na+ +OH- + HCl -> Na+ + H2O + Cl- (As you can see, by separating the ions, you can see that Na+ is merely a spectator ion)