Question

What happens when a solution of metal oxide is tested with red litmus and blue litmus?

Answer 1

Metallic oxides are generally basic in nature.

When metal oxides react with acid they form respective metallic salt and hydrogen.

Acid + Metal Oxide => Metal Salt + Hydrogen

This is similar to reaction where base comes instead of Metallic oxides. Hence it can be concluded that Metal oxide is a base.

So as mentioned above, red litmus paper turns blue when it’s reacted with bases and Blue litmus paper remains the same colour.  

Answer 2

Answer:

When metal oxides react with acid they form respective metal salt and water. ... Hence it can be concluded that Metal oxide is a base. So Bases generally turn Red litmus to blue. Hence the solution of any metal oxide will turn Red litmus to Blue but it has no effect on the Blue Litmus paper.