Question

How can calcium oxide be basic in nature if all non-metallic oxides are acidic in nature?

Answer 1

Dear Student

Metal oxide or Calcium oxide, CaO is basic in nature because -
these form hydroxides in aqueous solution, i.e.,
CaO + H₂O ​$\leftrightarrow$ Ca(OH)₂
MgO + H₂O ​$\leftrightarrow$ Mg(OH)₂

Non-metallic oxides are acidic in nature because these dissociate into their constituents ions in aqueous solution, giving out H⁺ and forming acids, like -
CO₂ ​+ H₂O ​$\leftrightarrow$ H₂CO₃ ​$\leftrightarrow$ H⁺ + HCO₃^-
SO₂ ​​+ H₂O ​$\leftrightarrow$ H₂SO₃ ​$\leftrightarrow$ H⁺ + HSO₃^-

Regards