Question

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

Answer 1

Answer:

1 . $Al_2O_3$

2. $TiO_2$

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.