Percentage Of Iconic Character
Chemical Bonding of Class 11
PERCENTAGE OF IONIC CHARACTER
Every ionic compound having some percentage of covalent character according to Fajan’s rule. The percentage of ionic character in a compound having covalent character, can also be calculated by the following equation.
The percent ionic character =
The example given above is of a very familiar compound called HF. The % ionic character is nearly 43.25%, so the % covalent character is (100 – 43.25) = 56.75%. But from the octet rule HF should have been a purely covalent compound but actually it has some amount of ionic character in it which is due to the electronegativity difference of H and F. Similarly knowing the bond length and observed dipole moment of HCl, the % ionic character can be known. It was found that HCl has 17% ionic character. Thus it can be clearly seen that although we call HCl and HF as covalent compounds but it has got appreciable amount of ionic character. So from now onwards we should call a compound having more of ionic less of covalent and vice versa rather than fully ionic or covalent.