Conjugate acids and bases

Question

What are conjugate acids and bases?

Answer 1

A conjugated acid is the protonated form of a molecule and a conjugated base is a molecule's deprotonated form.

For example, consider the equation:

HA + B ⇔ A^- + HB⁺

HA is an acid and A^- is its conjugated base.

B is a base and HB⁺ is its conjugated acid.

An example with molecules is as follows:

NH₃(aq) + H₂O ⇔ NH₄⁺(aq) + ^-OH(aq)

NH₃ is a base and its conjugate acid is NH₄^+.

H₂O is acting as an acid (in this example) and its conjugate base is ^-OH.

One easy trick to remember is to follow the proton.