Basic anhydride A metal oxide that reacts with

Basic anhydride A metal oxide that reacts with water to form a base. 

If a hydroxide formed by a metal oxide is water-soluble, it dissolves to form a basic solution. An oxide that reacts with water to form a basic solution is called a basic oxide or a basic anhydride. Table 7A on the next page lists oxides that form basic solutions with water. 

Oxides of metals are called basic anhydrides (or basic oxides) because many of them combine with water to form bases with no change in oxidation state of the metal (Figure 6-8). Anhydride means without water in a sense, the metal oxide is a hydroxide base with the water removed. Metal oxides that are soluble in water react to produce the corresponding hydroxides. 

Many oxides of metals that have a +1 or +2 charge are called basic oxides (basic anhydrides), because they will react with acids. 

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