Answer: IBr has the smallest percentage ionic character amongst the given compounds.
Explanation: Percentage ionic character is calculated by using the formula:
....(1)
where,
= difference in the electronegativies of the element forming a compound.
Electronegativity of H = 2.1
Electronegativity of F = 3.98
Electronegativity of Li = 0.98
Electronegativity of I = 2.66
Electronegativity of Br = 2.96
Electronegativity of Cl = 3.16

Putting this in equation 1, we get:
![\%\text{ Ionic character of HF}=[16(0.188)+3.5(1.88)^2]=42.45\%](https://tex.z-dn.net/?f=%5C%25%5Ctext%7B%20Ionic%20character%20of%20HF%7D%3D%5B16%280.188%29%2B3.5%281.88%29%5E2%5D%3D42.45%5C%25)

Putting this in equation 1, we get:
![\%\text{ Ionic character of HF}=[16(3)+3.5(3)^2]=79.5\%](https://tex.z-dn.net/?f=%5C%25%5Ctext%7B%20Ionic%20character%20of%20HF%7D%3D%5B16%283%29%2B3.5%283%29%5E2%5D%3D79.5%5C%25)

Putting this in equation 1, we get:
![\%\text{ Ionic character of HF}=[16(0.30)+3.5(0.30)^2]=5.115\%](https://tex.z-dn.net/?f=%5C%25%5Ctext%7B%20Ionic%20character%20of%20HF%7D%3D%5B16%280.30%29%2B3.5%280.30%29%5E2%5D%3D5.115%5C%25)

Putting this in equation 1, we get:
![\%\text{ Ionic character of HF}=[16(1.06)+3.5(1.06)^2]=20.89\%](https://tex.z-dn.net/?f=%5C%25%5Ctext%7B%20Ionic%20character%20of%20HF%7D%3D%5B16%281.06%29%2B3.5%281.06%29%5E2%5D%3D20.89%5C%25)
From the above calculations, we see that IBr has the smallest percent ionic character.