Question

H₂O is dipolar, whereas BeF₂ is not. It is because 

(a) the electronegativity of F is greater than that of O 

(b) H₂O involves hydrogen bonding whereas BeF₂ is a discrete molecule 

(c) H₂O is linear and BeF₂ is angular 

(d) H₂O is angular and BeF₂ is linear.

Answer 1

The correct option is: (d) H₂O is angular and BeF₂ is linear.

Explanation:

The overall value of the dipole moment of a polar molecule depends on its geometry and shape, i.e. vectorial addition of dipole moment of the constituent bonds. Water has angular structure with bond angle 105° as it has dipole moment. However BeF₂ is a linear molecule since dipole moment summation of all the bonds present in the molecule cancel each other.