Is oxide an acid

Answer 1

There is no single substance called oxide.

The oxide ion (O2-) is strongly basic though it cannot occur on its own as it is a charges species. It needs a positive ion to balance its charge.

The term oxide can also refer to any binary compound containing oxygen and another element. Some oxides, such as sulfur trioxide (SO3) are acidic. Most metal oxides such as calcium oxide (CaO) are basic. A few oxides such as water (H2O) are amphoteric, having both acidic and basic properties.