Question

$\begin{array}{cc}MgC{l}_2,& C{l}_2,\\ HF,& F_2\end{array}$

Some molecules are given in the box.
(a) Identify the ionic molecule.
(b) Write the reason for its ionic nature.
(c) Explain the polar nature of HF.

Answer 1

(a) $MgC{l}_2$
(b) As the electronegativity difference between the elements involved in bonding increases, it results into ionic bonding. When the electronegativity difference is above 1.7, there is a chance for the formation of an ionic compound.
(c) The polar nature of HF molecule can be explained as follows:
i. If the electronegativity values of the two atoms involved in bonding are different, the bonded electrons show a tendency to move closer towards the atom of high electronegativity.
ii. In the covalently bondend HF molecule, the atom F is more electronegative than H atom. As a result, the F atom gets a partial negative charge and the H atom gets a partial positive charge. These types of bonds are called as polar covalent bonds.
The partial charge on the atoms can be represented as follows
$H^{\delta +}-F^{\delta -}$