How Is Fractional Charge Calculated in Diatomic Molecules?

[physgirl]

Homework Statement

For this problem, I had to find the fractional charge given the dipole moment u and bond length R in a diaomic molecule (H-X, where X is a halogen)... I found that fractional charge by: fractional charge=u/(eR)
where e=elementary charge of an electron

I think that's correct?? So then using that, I said that percent ionic character in the bond is "fractional charge"*100%.

So then to find the effective fractional charge on the H and X atom, is that just +"fractional charge" on the H and -"fractional charge" on X?



So in short, if I found fractional charge between HCl to be 0.18 (would it be ok to do that by doing fractional charge=u/(eR)?), for instance, then percent ionic character would be 18% and effective fractional charge on H would be +0.18 and that on Cl would be -0.18?

 

[Gokul43201]

Looks good. As a doublecheck, you can compare with the % ionic character computed from the electronegativity difference.