Question
Which out of the two molecules - OCS and CS2 has a higher dipole moment and why ?
Solution
OCS has a higher dipole moment. CS2 is a linear molecule in which two C = S bonds are oriented in the opposite directions at an angle of 180°. The bond dipoles of C = S has some dipole moment, but due to the linear structure of CS2, the bond dipoles of two C = S bonds cancel each other. Therefore the resultant dipole moment of CS2 is zero. On the other hand, the bond dipoles of C = S and C = O bonds in OCS molecule do not cancel with other (O is more electronegative than S). Hence the resulting dipole moment of OCS molecule is not zero. Hence OCS has a higher dipole moment.
