Question

Consider the autoionization of liquid ammonia:

Label each of the species in the equation as an acid or a base and explain your answer.

Short answer

Acid: Proton Base: proton acceptor Conjugate base Conjugate acid

donor

Step-by-step solution

Labelling

Acid Base Conjugate Base Conjugate Acid

Reason

The first ammonia molecule, i.e., NH_3,gives up an H⁺ ion and converts it to NH₂^- ion, so it acts as an acid. The base formed after removing an H⁺ ion from acid is known as a conjugate base.

The second ammonia molecule accepts the given H⁺ ion, so it is acting as a base (according to Bronsted-Lowry definition), and the positive ion formed after accepting the H⁺ ion (NH₄⁺in this case) is known as conjugate acid.