Question

How do you calculate the dipole moment of a molecule?

Answer 1

Calculating a dipole moment numerically is actually fairly simple.

Explanation:

The strength of a dipole moment is expressed in units of the debye (D). 1 debye = 3.34x10^-30 coulomb/meter. The formula for calculating a dipole moment is as follows:
`mu=δ * d`
`mu` is the strength of the dipole moment.
δ is the amount of charge at either end of the dipole, and d is the distance between these charges.
While the above equation is the definition of dipole moment strength, normally the following constant is inserted into the equation:
`mu=4.8δ*d`
Example:
`mu=0.95D`
d=1.46A
Solve for δ
`0.95=4.8δ*1.46`
`δ=0.1356e`
where "e" is the symbol for electron charge, not the non-terminating mathematical constant "e". This electron charge can be considered as a percentage. In other words, one may consider the charge on this dipole moment as 13.56% partial positive and 13.56% partial negative.