Lewis structure of ICl₄⁻
36 valence electrons. Four I-Cl single bonds, with two lone pairs on I, so I has 12 electrons around it (an expanded octet).
Lewis structure
36 valence electronsFormal charges: I −1
Why this shape
- I has 7 valence electrons. In the Lewis structure it makes four single bonds to Cl and keeps two lone pairs, which leaves it a formal charge of −1.
- Steric number = four sigma bonds + two lone pairs = 6, so I is sp³d² hybridised.
- Six electron pairs point to the corners of an octahedron (octahedral electron geometry). With two lone pairs in place of atoms, the atoms make a square planar shape.
- The two lone pairs sit opposite each other, 180 degrees apart, so their repulsion is least and the four bonds lie in a square.
- The lone pairs balance each other, so the bonds are not pushed out of place and the angle stays at 90°.
- ICl₄⁻ is an ion with an overall charge of −1, so it is not described as polar or non-polar.
How to draw it
- Count the valence electrons: I 7 + 4 × Cl 7 + 1 for the ⁻ charge = 36 valence electrons, 18 pairs.
- Put I in the middle and join it to the four outer atoms with single bonds.
- Give each outer atom lone pairs until it has an octet (H needs only two electrons), then put any electrons left over on the central atom.
- Result: four I-Cl single bonds, with two lone pairs on I, so I has 12 electrons around it (an expanded octet).
- Formal charge = valence electrons − lone pair electrons − number of bonds. Here: I −1.
Class 11, Chapter 4 Chemical Bonding and Molecular Structure.
Lewis structure of ICl4-: quick answers
How many valence electrons are in ICl4-?
I 7 + 4 × Cl 7 + 1 for the ⁻ charge = 36 valence electrons, 18 pairs.
What are the formal charges in the Lewis structure of ICl4-?
I −1; every other atom is zero. Formal charge = valence electrons - lone pair electrons - number of bonds.
How many lone pairs are in the Lewis structure of ICl4-?
14 in all, 2 of them on the central I.