Question

Of the two molecules OCS and CS₂ which one has higher dipole moment value? Why?

Answer 1

OCS and CS₂

The dipole moment μ_OCS = 0.7 149 ± 0.0003 Debye.

CS₂ :

S = C = S

In CS₂ , the bond dipoles of 2C = S have same values and bond dipoles cancel each other so dipole moment of CS₂ is zero. Among OCS and CS₂ , OCS has a higher dipole moment because in OCS oxygen is more electronegative than sulphur and C = S and C = O bonds in OCS molecules do not cancel each other.

On the other hand CS₂ , due to linear structure, the bond dipole of two C = S bonds cancel each other. On the other hand, CS₂ due to linear structure, the bond dipoles of two C = S bonds cancel each other and the resultant dipol’s moment value is zero. So OCS has a higher dipole moment than CS₂ .