Identify the Acid, Base, Conj Acid, Conj Base. I can't remember, what do I do? .NH3 + N2H5+ <--> NH4+ + N2H4.

By: Guest
Date: Wed-Dec-7-2011-

Answer 1

OH (((-))) base

H3O (((+))) acid

+ = more acidic - = more basic

NH3 is 1- compared to NH4+ therefore NH3 is the base and NH4+ is the conjugate acid. The opposite is true for N2H(4/5)

Answer 2

There is a very easy way to identify the parts of a Bronsted-Lowry acid/base reaction.

An acid is always a substance that donates a proton.

The conjugate acid also donates a proton, but in the OPPOSITE direction.

A base is always a proton acceptor.

The conjugate base accepts a proton, but in the OPPOSITE direction.

NH3 + N2H5+ <--> NH4+ + N2H4

base .. acid.......conj acid...conj base

The N2H5+ donates a proton and NH3 accepts it to make NH4+.

In the reverse reaction, NH4+ donates a proton and N2H4 accepts it in order to make the reactants. That makes NH4+ the conjugate acid and N2H4 the conjugate base.

======== Follow up ========

I think Ged would be better served by simply referring to the definitions of an acid and a base in the Bronsted-Lowry theory. It's much easier than this + vs - "explanation".

What about this reaction:

HSO4^- + H2O <==> H3O+ + SO4^2-

In this case the "negative" species is the acid, and the neutral compound is the base. That's just the reverse of Ged's suggestion.

But using the Bronsted-Lowry definitions of an acid and a base, we can easily see why HSO4- is the acid, because it donates a proton to water, which is the proton acceptor and therefore, the base.

In the reverse reaction H3O+ donates a proton, which makes it the conjugate acid, to SO4^2-, the conjugate base.

Wait a minute. I see where Ged is headed. He's saying that the + vs - constitutes the conjugate acid/base pair. According to his explanation, HSO4- is more positive than SO4^2- which makes HSO4- an acid and SO4^2- a conjugate base. And H2O is more negative than H3O+, which makes H2O the base and H3O+ the conjugate acid.

Ok. I get it. That works, too. It's not what Bronsted and Lowry had in mind, I'm sure, but it does work.

[d] By: Guest
Date: Unknown---
What is 1 + 100

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