(a) A diatomic moleculae has a dipole moment of 1.2 D. If the bond distance is 1.0Å, What fraction of an electronic charge 'e' exists on each atom ? (b) The dipole moment of LiH is 1.964xx10 ^(-29) C-m and the interatomic distance between Li and H in this molecule is 1.596Å. What is the per cent ionic character in LiH?

(a) A diatomic moleculae has a dipole moment of 1.2 D. If the bond dis

1.	(a) A diatomic moleculae has a dipole moment of 1.2 D. If the bond distance is 1.0Å, What fraction of an electronic charge 'e' exists on each atom ? (b) The dipole moment of LiH is 1.964xx10 ^(-29) C-m and the interatomic distance between Li and H in this molecule is 1.596Å. What is the per cent ionic character in LiH?
Answer» Solution :(a) Partical charge `=("DIPOLE moment ")/("BOND dis tance ")` `= (1.2 XX 10 ^(-8)"esu cm")/(1.0 xx 20 ^(-8)cm) = 1. 2 xx 10 ^(-10))=0.25 = 25%`ofe. (B) The dipole moment of `100%` ionic molecule `(Li ^(+)H^(-))` = (1 elecronic charge) (interatomic DISTANCE) ` = (1.602 xx 10 ^(-19) C) ( 1.596 xx 10 ^(-10)m)` `= 2.577 xx 10 ^(-29)Cm` Fractional ionic character `= ("Exp. value of dipole moment")/("Theoretical value of dipole moment") = ( 1. 964 xx 10 ^(-29))/(2.557 xx 10 ^(-29))= 0.768` The bond in LiH is `76.8%` ionic.