# Question #97f87

May 6, 2015

Yes

#### Explanation:

Yes, pure water does contain ions due to a process called the autoionization (or self-ionization) of water.

That happens because water can act both as an acid, donating a proton, ${H}^{+}$, to another water molecule, which acts as a base.

The reaction results in the formation of the hydronium ion, or ${H}_{3} {O}^{+}$, and of the hydroxide ion, $H {O}^{-}$.

However, the concentration of hydronium and hydroxide ions will be very, very small; in fact, the equilibrium that's established in solution lies so far to the left, that only 18 in ${10}^{10}$ molecules of water will undergo autoionization.