Why is latent heat of fusion of solid carbon dioxide less than that of silicon dioxide ?

Explanation

Silicon dioxide `(SiO_(2))` is a covalent solid in which the atoms are linked by covalent bonds resulting in giant crystal. On the other hand, solid carbon dioxide (or dry ice) is a molecular solid in which the molecules of `CO_(2)` are held together by weak van der Waal's froces of attraction. Therefore, attractive forces in silicon dioxide are more than in solid carbon dioxide. As a result, the the latent heat of fusion of the former is more.