Identify all correct statements about the ionization of water.

Check all that apply.

Dissociation of water is reversible.
Dissociation of water is not reversible.
Water ionizes to form hydroxide and hydronium ions.
Water ionizes to form peroxide and hydronium ions.
Dissociation of water produces equal masses of OH- and H+.
Dissociation of water produces equal numbers of OH- and H+.

1 answer

Here are the correct statements about the ionization of water:

  1. Dissociation of water is reversible. - True. The ionization of water can go both ways, producing hydronium (H₃O⁺) and hydroxide (OH⁻) ions, and can also recombine to form water.

  2. Dissociation of water is not reversible. - False. As mentioned above, the dissociation of water is indeed reversible.

  3. Water ionizes to form hydroxide and hydronium ions. - True. The dissociation of water can be expressed as: \( H_2O \rightleftharpoons H^+ + OH^- \), or more commonly as: \( 2 H_2O \rightleftharpoons H_3O^+ + OH^- \).

  4. Water ionizes to form peroxide and hydronium ions. - False. Water does not ionize to form peroxide; it primarily forms hydroxide and hydronium ions.

  5. Dissociation of water produces equal masses of OH⁻ and H⁺. - False. The masses are not equal, as the mass of a hydroxide ion (OH⁻) is slightly different from that of a hydrogen ion (H⁺).

  6. Dissociation of water produces equal numbers of OH⁻ and H⁺. - True. The dissociation of water produces equal moles (and thus equal numbers) of hydroxide (OH⁻) and hydrogen (or hydronium, H₃O⁺) ions.

In summary, the correct statements are:

  • Dissociation of water is reversible.
  • Water ionizes to form hydroxide and hydronium ions.
  • Dissociation of water produces equal numbers of OH⁻ and H⁺.