Which of the following oxides is acidic in nature?

1. B2O3

2. Al2O3

3. Ga2O3

4. In2O3

 
 


Hint: Down the group basic character increases.

The acidic nature of oxides changes from acidic to basic through amphoteric on moving down the group.
B2O3More acidic
less basic, Al2O3 and Ga2O3Amphoteric, In2O3 and Tl2O3Basic