# How do you draw the lewis structure of IF_4^- ?

Jun 24, 2016

Here are the steps that I follow when drawing a Lewis structure.

#### Explanation:

1. Decide which is the central atom in the structure.

That will normally be the least electronegative atom ($\text{I}$).

2. Draw a skeleton structure in which the other atoms are single-bonded to the central atom:

3. Draw a trial structure by putting electron pairs around every atom until each gets an octet.

4. Count the valence electrons in your trial structure (32).

5. Now count the valence electrons you actually have available.

1"I" + 4"F" + "1e"^"-" = 1×7 + 4×7 +1 = 7 + 28 +1 = 36.

The trial structure has four extra electrons.

6. Add these extra electrons to the central atom.

8. Calculate the formal charge on each atom.

The $\text{I}$ atom has a formal charge of -1.

We place this charge on the iodine atom, and we get the Lewis structure of $\text{IF"_4^"-}$.