The Arrhenius Definition of Bases

NaOH is an Arrhenius base because it produces OH− ions in solution.

NaOH is an ionic compound and contains Na+ ions and OH− ions.

When NaOH is added to water, it dissociates into its component ions.

Molecular compounds containing an OH group, such as methanol, CH3OH, do not dissociate in solution and therefore do not act as bases.

• Base—A base produces OH− ions in aqueous solution.