someone please help me on this!!!?

Question

Lithium forms a gaseous molecule with hydrogen, LiH. The bond length is 159 pm and the dipole moment is 5.884 D. What is the extent of electron transfer from Li to H in LiH? Compare the answer to that for LiF (µ = 3.326 D, bond length= 156 pm).
LiH

LiF

Answer 1

1 D= 10^-18 esu*cm
So we have to express the length in cm.
159 pm= 1.59*10^-8 cm

For 1 e the charge is 4.8*10^-10 esu, so for a 100% electron transfer in LiH we should have
μ= z*r =(4.8*10^-10) * (1.59*10^-8) =7.632 *10^-18 esu*cm =7.632 D

So the % of the transfer is 5.884/7.632= 77%

For LiF
μ= z*r =(4.8*10^-10) * (1.56*10^-8) = 7.488 D
and % is 3.326/7.488 = 44%

It is highly unlikely that LiF has such a small % of ionic bonding and cannot have smaller % than LiH since F is more electronegative than H. I think you have mistyped at least one of the values. You can also check http://www.chemistry.mcmaster.ca/esam/Chapter_7/section_3.html