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] )