Final answer:
The major product when water molecules react is a hydronium ion (H3O+) and a hydroxide ion (OH-), an autoionization process demonstrated by the equation 2H₂O → H3O+ + OH-.
Step-by-step explanation:
When water molecules react with each other, the major product of this reaction is the formation of a hydronium ion (H3O+) and a hydroxide ion (OH-). In this process, one water molecule donates a proton (H+) becoming a hydroxide ion, while another water molecule accepts the proton, forming a hydronium ion. This is a classic example of autoionization of water and is represented by the equation 2H₂O → H3O+ + OH-.
The reaction can be described in more complex scenarios, such as when an acid like HF reacts with water, producing H3O+ and F-, or in the process of acidic hydrolysis where water interacts with an ester. Similarly, acetic acid (CH3COOH) in water establishes an equilibrium with acetate ions (CH3COO-) and hydronium ions.