Classify each molecule as polar or nonpolar.
Here, we are going to classify the given molecules as polar or nonpolar..
In case of heteronuclear molecules(containing different atoms), the shared electron pair between the two atoms gets displaced more towards the more electronegative atom. The resultant covalent bond is called polar covalent bond.
As a result of polarisation, the molecule possesses the dipole moment which can be defined as the product of the magnitude of the charge and the distance between the centres of positive and negative charge. Further, dipole moment is depicted by a small arrow with tail on the positive centre and head pointing towards negative centre.
On the other hand, when covalent bond is formed between two similar atoms, for example, in H2, O2, Cl2 or N2, the shared pair of electron is equally attracted by the two atoms. As a result, the electron pair is situated exactly in between the two identical nuclei. The bond so formed is called nonpolar covalent bond.
The structure of CS2 molecule is given below:
CS2 molecule is a linear molecule with 2 sulfur atoms attached to both ends through double bond. Both the sulfur atoms are symmetrically arranged. Polarity results from an unequal sharing of valence electrons but due to the symmetrical arrangement of sulfur atoms, there is no region of unequal sharing in CS2 and hence, it is nonpolar.
The structure of SO2 molecule is given below:
SO2 molecule is a bent shaped molecule with 2 oxygen atoms attached to both ends through double bond at an angle 0f 119o. Due, to this unsymmetrical arrangement in the molecule, a region of unequal sharing arises.The oxygen atoms at the bottom are more electronegative compared to the top where the lone pair of electron is. Hence, the molecule is polar.