Question

If observed dipole moment and calculated dipole moment is given then what is the % ionic charactor formula

Answer 1

The calculated dipole moment is charge on electron * radius of molecule

That's off a bit, the calculated dipole moment (calculated assuming one electron has been completely transferred from hydrogen to bromine) is dependent on the bond length (interatomic spacing), not the radius.

μ100%μ100%μ100%=electron charge×interatomic spacing=(1.6×10−19) C×(1.41×10−10) m=2.26×10−29 C mμ100%=electron charge×interatomic spacingμ100%=(1.6×10−19) C×(1.41×10−10) mμ100%=2.26×10−29 C m

As you point out,

% ionic character=[μobs][μ100 %]=[2.6×10−30][2.26×10−29]=0.12=12 %

Answer 2

Here's the formula

% Ionic Character

= (Observed μ / calculated μ) × 100

[Here, μ is dipole moment]

Hope it helps You...!!!

(^_^)