1. Tardigrade
  2. Question
  3. Chemistry
  4. The order of which of the following oxides is arranged according to decreasing basic nature?

Question Error Report

Thank you for reporting, we will resolve it shortly

Back to Question

Q. The order of which of the following oxides is arranged according to decreasing basic nature?

Classification of Elements and Periodicity in Properties

Solution:

Applying Fajans’ rule, the lower the charge; the more is ionic and the more is basic and vice versa.
Moreover, small cation, large anion, high charge and presence of $d$ electrons mean more covalent and more acidic.
Therefore, decreasing order of basic nature is
image
Size $Al^{3+} > Cu^{2+}$ and presence of d electron in $Cu^{2+}$ makes it less basic (or more acidic) than $Al_2O_3$.