Question

Which reactions show an oxide acting as a base?

Check all that apply.

K2O(s)+H2O(l)→2K+(aq)+OH−(aq)
SO3(l)+H2O(l)→ H+(aq)+HSO4−(aq)
Al2O3(s)+6OH−(aq)+3H2O(l)→2Al(OH)−4(aq)
Al2O3(s)+6H+(aq)→2Al3+(aq)+3H2O(l)
SiO2(s)+2OH−(aq)→ SiO3−(aq)+H2O(l)
MgO(s)+2H+(aq)→Mg2+(aq)+H2O(l)

Answer 1

A base is a proton acceptor, according to the theory of Bronsted-Lowry. The oxides of metals are anhydrides, it is the result of the Arrhenius base once the water molecules are removed. Thus, the first, fourth and last chemical equations are considered as a base.