B. Bases Understandings and Fundamental Concepts Bases may be defined in terms of their characteristic properties. Bases cause color changes in acid-base indicators. Bases react with acids to form water and a salt. These properties form the basis of the operational definition of a base. Some examples of the relative degree of ionization are shown in the Reference Tables for Chemistry.
Strong bases have a caustic action on the skin.
Go to top . A base is a substance that yields hydroxide ions as the only negative ions in aqueous solution. The characteristic properties of bases in aqueous solution are due to the hydroxide ion. According to the Arrhenius definition, the only bases are hydroxides. Go to top .