Question

How would you arrange the following bonds in order of increasing ionic character: $C-F, \ O-F, \ H-F,$ and $Na-F$?

Answer 1

Hint: Electronegativity is the tendency of an atom to attract the shared pair of electrons towards itself. It is found that Fluorine is the most electronegative element.

Complete answer:
- It is found that if the electronegativity difference in between the two atoms is very large then, then we will get more ionic bonds and if the difference in between the two atoms is very small then, then we will get more covalent bonds.
- It is found that when we move down the group in the periodic table, electronegativity value decreases. Whereas, electronegativity value basically increases as we move from left to the right side of the periodic table. So, if we look at the periodic table then we can rank the given elements as:
F – most electronegative
O
C
H
Na – least electronegative
- Hence, the greatest electronegativity difference is found to be in Na-F that is more ionic character, and smallest electronegativity difference is found to be in C-F, O-F, H-F, that is less ionic character.
- Hence, we can arrange the given bonds in order of increasing ionic character as: O-F < C-F < H-F < Na-F.

Note:
- We can also arrange them in another way by looking up the values of Pauling electronegativity for each element. Then we can work out actual values of electronegativity difference for each pair, that makes the ranking even easier.
- It is found that ionic character basically increases in direct proportion with the difference in the electronegativity between the two bonded atoms.