Write the significance/applications of dipole moment.
The significance and applications of dipole moment include:
First, it helps in determining the polar or nonpolar nature of covalent bonds and molecules. A heteronuclear molecule like HF possesses a dipole moment due to the displacement of the shared electron pair towards the more electronegative atom, indicating a polar covalent bond.
Second, it is used to predict the geometry or spatial arrangement of bonds in polyatomic molecules. For example, a zero dipole moment indicates a symmetrical structure like linear or , whereas a non-zero dipole moment indicates an asymmetrical shape like bent or trigonal-pyramidal .
Finally, it helps in comparing the resultant bond moments and the effect of lone pairs in molecules, such as understanding why has a greater dipole moment than .
Explanation
The textbook context explains that dipole moment arises from the polarisation of bonds in heteronuclear molecules, distinguishing polar from nonpolar bonds. It also highlights that for polyatomic molecules, the net dipole moment depends on the spatial arrangement of bonds, allowing us to deduce molecular geometry (e.g., zero dipole moment for linear vs non-zero for bent ). Furthermore, the context uses and to show how dipole moment helps analyze the directional effects of lone pairs and bond dipoles.