In the equilibrium reactionH2O(l) + HX(aq) ⇌ X–(aq) + H3O+(aq),H2O is a hydrogen ion and HX is a hydrogen ion

The statement is not entirely correct. In the given equilibrium reaction, H2O (water) acts as a base and HX (a generic acid) acts as an acid.

Here's the step-by-step breakdown:

1. HX, being an acid, donates a proton (H+) to H2O. This is why we say HX is a proton donor.

2. H2O accepts the proton from HX, becoming H3O+ (hydronium ion). This is why we say H2O is a proton acceptor or a base.

3. The remaining part of the HX molecule after it has donated its proton becomes X- (the conjugate base of the acid).

So, in this reaction, H2O is not a hydrogen ion, it is a base because it accepts a hydrogen ion. Similarly, HX is not a hydrogen ion, it is an acid because it donates a hydrogen ion.