Question

$HCl$ gas is covalent and $NaCl$ is an ionic compound. This is because

• A. Sodium is highly electro +Ve
• B. Hydrogen is a non-metal.
• C. $HCl$ is a gas.
• D. Electronegativity difference between $H$ and $Cl$ is less than 2.1.

Answer 1

Answer: (D)

$HCl(g)$ is covalent whereas $NaCl$ is an ionic solid due to small difference in their electronegativities.

In HCl, the difference in electronegativity of $H$ and Cl-atoms is less than $2.10$, whereas in $NaCl$, the difference in electronegativities of Na and Cl-atoms is more than $2.10$.

Electronegativity of $(Cl)=3.00$ (approx. value)

Electronegativity of $(Na)=0.88$ (approx. value)

Electronegativity difference $=2.12$