When two water molecules undergo auto-ionization (self-ionization), what are the products formed?

• A. H+ and O2-
• B. H2O2 and H2
• C. H2O and H+
• D. H3O+ and OH-

Answer: (D)

Verified step by step guidance

1. Understand that auto-ionization (or self-ionization) of water involves two water molecules interacting to produce ions.
2. Recall that in this process, one water molecule donates a proton (H+) to another water molecule.
3. Recognize that the water molecule accepting the proton becomes a hydronium ion, represented as \(\mathrm{H_3O^+}\).
4. Identify that the water molecule losing the proton becomes a hydroxide ion, represented as \(\mathrm{OH^-}\).
5. Therefore, the products formed from the auto-ionization of water are \(\mathrm{H_3O^+}\) and \(\mathrm{OH^-}\) ions.