Question

Identify polar molecules among the following molecules.

• A. $N_2$
• B. $H_{2}O$
• C. $H_2$
• D. $\mathrm{HCl}$

Answer 1

Answer: (B), (D)

The correct options are
B $H_{2}O$
D $\mathrm{HCl}$

$\bullet$ Electronegativity is the ability of an atom to attract the shared pair of electrons in a molecule.

$\bullet$ When atoms of elements with different electronegativities form a molecule, the atom with higher electronegativity attracts the shared pair of electrons towards itself.



$\bullet$ This results in formation of partial positive and negative charge on the atoms (positive and negative poles). Such molecule is called a polar molecule.

$\bullet$ $\text{HCl}$ and ${\text{H}}_2\text{O}$ have atoms with large electronegativity difference. Therefore, they are polar molecules.