Question

Fe_2O_3(s) and Al_2O_3 have similar chemical properties, some similarities are due to the oxides having similar lattice energies. Give two reasons why the lattice energies of the oxides are similar.

Answer 1

The lattice energies of Fe2O3(s) and Al2O3 are similar due to the smaller size of the O2- ion compared to the Se²- ion.

Step-by-step explanation:

In these two ionic compounds, the charges Z* and Z¯ are the same, so the difference in lattice energy will depend upon Ro. The O2- ion is smaller than the Se²-ion. Thus, Al2O3 would have a shorter interionic distance than Al2Se3, and Al2O3 would have the larger lattice energy.