When water ionizes, which ions are produced?

• A. Na+ and OH-
• B. H3O+ and OH-
• C. H2O+ and O2-
• D. H+ and Cl-

Answer: (B)

Verified step by step guidance

1. Understand that water ionizes through a process called autoionization or self-ionization, where two water molecules interact to produce ions.
2. Recall the chemical equation for water ionization: \(\mathrm{2\ H_2O \rightleftharpoons H_3O^+ + OH^-}\), where one water molecule donates a proton (H+) to another water molecule.
3. Identify the ions produced: the hydronium ion (\(\mathrm{H_3O^+}\)), which is a water molecule with an extra proton, and the hydroxide ion (\(\mathrm{OH^-}\)), which is water that has lost a proton.
4. Note that \(\mathrm{Na^+}\) and \(\mathrm{Cl^-}\) are ions from common salts, not from water ionization, and \(\mathrm{H_2O^+}\) and \(\mathrm{O^{2-}}\) are not typical ions formed in water ionization.
5. Conclude that the correct ions produced when water ionizes are \(\mathrm{H_3O^+}\) and \(\mathrm{OH^-}\).