Chemistry - PERIODIC TABLE Question with Solution | TestHub

The incorrect order is (C) Melting point: $\mathrm{NaCl}<\mathrm{MgC}{\mathrm{l}}_2<\mathrm{AlC}{\mathrm{l}}_3$. The melting points generally increase with increasing ionic character and lattice energy. $\mathrm{NaCl}$ is ionic, $\mathrm{MgC}{\mathrm{l}}_2$ is more covalent, and $\mathrm{AlC}{\mathrm{l}}_3$ is predominantly covalent with a dimeric structure, leading to a decrease in melting point.