What is a conjugate acid or base?

[MHarrold_1E]

What exactly is a conjugate acid or base? Do all acids have a conjugate base?

[Ria Nawathe 1C]

A conjugate acid is the resulting species when a base accepts a proton, and a conjugate base is the species that results when an acid gives off a proton.

For example, the conjugate acid of the base NH3 is NH4+, as NH3 + H+ --> NH4+. The conjugate base of H2SO4 is HSO4-, since H2SO4 donating a proton leaves the anion HSO4-.

Hope this helps!

[Hannah Alltucker 3L]

A conjugate base is what remains after the acid has given up a proton (So the acid - one H+). A conjugate acid is the base once it has gained that proton (so the base + one H+). Because acid/base reactions also have the ability to go in the reverse direction, I like to think of the conjugates as what would act as the acid and base in a reverse reaction.

Another good thing to remember is that the strength of an acid can be considered as how well that acid remains its conjugate base, a strong base can be considered as how well a base remains its conjugate acid!

All acids and bases will have a conjugate!

[Alara Aygen 3K]

If you are given a base and asked to find the conjugate acid, you need to add one H atom since Bronsted bases are proton acceptors.
If you are given an acid and asked to find the conjugate base, you need to remove one H atom, since the Bronsted acids are proton donors.

[jessicasilverstein1F]

These can be confusing to me. I think of it like this:
A conjugate acid is the resulting formula when a base accepts a proton (H+), and a conjugate base is the species that results when an acid gives off a proton (H+).

[Vanshika Bhushan 1A]

A conjugate acid contains one more H atom and one more + charge than the base that formed it. A conjugate base contains one less H atom and one more - charge than the acid that formed it. All acids and bases have conjugate bases.