2NH3 <--> NH4+ + NH2-

In liquid ammonia the reaction represented above occurs. In the reaction, what does the NH4+ act as?

A catalyst? And acid & a base? the conjugate acid of NH3? The reducing agent? The oxidizing agent?

acid

Not a catalyst. N has the same oxiation state on both sides; therefore, it can't be oxidized or reduced or an oxidizing or reducing agent. This reaction is like the ionization of water. Look at what it does.

H2O + H2O ==> H3O^+ + OH^-.
One molecule of H2O has acted as a base (to form the H3O^+ ion) and the other molecule of H2O has acted as an acid (donating that H^+ to the first molecule of H2O). Isn't that what NH3 has done?
NH3 + NH3 ==> NH4^+ + NH2^-

If #1 NH3 has accepted a proton, to become the NH4^+ ion, then #1 ammonia must be the _______ and NH4+ must be the conjugate _________.

catlyst

To determine what NH4+ acts as in the given reaction, we need to examine its role and properties. NH4+ is called an ammonium ion, which is formed when an ammonia (NH3) molecule accepts a proton (H+) from an acid.

In the given reaction, NH4+ is formed when NH3 reacts with a proton (H+). This proton transfer reaction can be represented as:

NH3 + H+ -> NH4+

Based on this reaction, we can conclude that NH4+ acts as a conjugate acid of NH3 because it is formed when NH3 accepts a proton. In this case, NH3 is the base, and NH4+ is its conjugate acid.

Therefore, the correct answer is that NH4+ acts as the conjugate acid of NH3 in the given reaction. It is not a catalyst, an acid & a base simultaneously, a reducing agent, or an oxidizing agent in this particular reaction.

it is the conjugate base of NH3