Question

Name two compounds with more exothermic lattice energies than scandium oxide and justify your choice.

Answer 1

1 .
`Al_2O_3`

2.
`TiO_2`

Step-by-step explanation:

The more stable the ionic compound, the more is it lattice energy.

• The more the charge on the cation and the anion, the greater is the lattice energy.
• The less the size of the cation and the anion, the greater is the lattice energy.

Scandium oxide (
`Sc_2O_3`) is an oxide in which
`Sc^(3+)` behaves as cation and
`O^(2-)` behaves as anion.

The compounds which has higher lattice energy than scandium oxide are:

1 .
`Al_2O_3`

This is because the charge are same on the cation and the anion as in the case of the Scandium oxide but the size of the cation
`Al^(3+)` is smaller than
`Sc^(3+)`. Thus, this corresponds to higher lattice energy.

2.
`TiO_2`

This is because the charge on the cation
`Ti^(4+)` is greater than that of
`Sc^(3+)` and also the size of the cation
`Ti^(4+)` is smaller than
`Sc^(3+)`. Thus, this corresponds to higher lattice energy.