Chemical Bonding - Dipole Moment 2

Chemical Bonding - Dipole Moment 1

Chemical Bonding Dipole Moment || Important Orders || Chemistry for NEET/JEE 2020

Dipole||Dipole Moment

The bond angle and dipole moment of water respectively are :

Coordinate Bond|Dipole Moment|Summary

Polar covalent molecules exhibit dipole moment. Dipole moment is equal to the product of charge separation , q and the bond length d for the bond. Unit of dipole moment is debye. One debye is equal to 10^(-18) esu cm. Dipole moments is a vector quantity. It has both magnitude and direction. Hence, dipole moment of a molecule depends upon the relative orientation of the bond dipoles, but not on the polarity of bonds alone. A symmetrical structure shows zero dipole moment. Thus, dipole moment helps to predict the geometry of a molecules. Dipole moment values can be distinguish between cis- and trans- isomers, ortho, meta and pare-forms of a substance, etc. Q. Which is a polar molecule?

Chemical bonding between two atoms is necessarily associated with an electrical moment arising out of the difference in electroegativity of two atoms. This means that every bond carries with it an electrical moment called the ''bond moment''. The dipole moment of a molecule is really the vectorial sum of the individual bond moment present in it. To compute the dipole moment it is necessary to find out the values of various bond moment. In the following table, dipole moment of different bonds are as given. {:(,rarr,rarr,rarr),("Bond",H-C,C-Cl,C=0),("Bond moments",0.4 D,1.5 D,2.5 D):} The group moments of few groups as given {:("Group",NO_(2),OH,CN,CH_(3)),("Direction of dipole","Towards N","Towards O","Towards N","Away from "CH_(3)),("Dipole moment",4D,1.6D,3.8D,0.4D):} The bond angle in H_(2)S is 97^(@) and its dipole moment is 1.5 D. The S-H bond distance is 0.15 nm. Therefore, approximate percentrage ionic cjaracter pf S-H bond is (neglect the effect of dipole moment of lone pair on sulphur atom in H_(2)S ). (Given : [cos 97^(@)=-0.121 and sqrt(0.88)=0.94] )