Question

Which one of the following is a covalent compound:

• A. $NaCl$
• B. ${AlCl}_3$
• C. ${MgCl}_2$
• D. ${CCl}_4$

Answer 1

The correct option is D

${\mathrm{CCl}}_4$

Covalent compounds are those compounds in which the atoms share one or more pairs of electrons present in their valence shells.

Electrovalent compounds are those compounds in which the complete transfer of electrons takes place from one atom to another atom.

A ${\mathrm{CCl}}_4$ molecule has four chlorine $\left(\mathrm{Cl}\right)$ atoms and only one carbon $\left(\mathrm{C}\right)$ atom.

Each chlorine atom is one short of an octet configuration and carbon is a four-electron sort of a complete valence shell of eight.

Chlorine shares four electrons with the carbon atom results, complete outer shells for carbon and four chlorine atoms.

The bond between carbon and chlorine is established by sharing electrons, so it is a covalent bond.

As a result, ${\mathrm{CCl}}_4$ is classified as a covalent compound.

Sodium chloride$\mathrm{NaCl}$, Aluminum chloride ${\mathrm{AlCl}}_3$ and Magnesium chloride ${\mathrm{MgCl}}_2$are formed by ionic bonds.

Sodium $\left(\mathrm{Na}\right)$ requires to lose one electron to attain a stable noble gas configuration and Chlorine $\left(\mathrm{Cl}\right)$ requires to gain one electron to reach a stable noble gas configuration. So, chlorine accepts an electron transferred by Sodium to form sodium chloride by an ionic bond.

Similarly, Aluminum chloride and Magnesium chloride are formed.

So, all of the three compounds Sodium chloride, Aluminum chloride and Magnesium chloride are ionic compounds.

Hence, option (D) is the correct answer.