Question

Which is more covalent $\mathrm{NaCl}\mathrm{or}{\mathrm{MgCl}}_2$?

Answer 1

1. Sodium and Magnesium are the chemical elements that belong to the first and second groups of the periodic table respectively.
2. Sodium and Magnesium both can lose their electrons to form a cation.
3. But in the case of Chlorine, it accepts the electrons to form anions.
4. The Magnesium loses two of its electron to form ${\mathrm{Mg}}^{2+}$and lose of one electron of Sodium to form ${\mathrm{Na}}^{+}$.
5. The larger is the cationic size of the element greater the polarizing power.
6. Greater is the polarising power, and more covalent is the element.
7. Sodium chloride forms by combining the Sodium and Chlorine atom to form an ionic bond.
8. Thus, Magnesium has a more positive charge on it which increases the charge density and therefore polarising power increases.
9. Hence Magnesium chloride (${\mathrm{MgCl}}_2$) is more covalent in nature compared to Sodium chloride ($\mathrm{NaCl}$).