Answer
0.41 electron charge
Work Step by Step
bond dipole moment (in debyes) = 4.8 $\times$ electron charge $\times$ distance between the charges (in angstroms)
Thus,
2.4D = 4.8 $\times$ electron charge $\times$ 1.23Å
= $\frac{2.4D}{4.8\times 1.23Å }$ = 0.41 electron charge.
