HOCl Lewis Structure
The Lewis dot structure of hypochlorous acid (HOCl): single bonds H-O-Cl, with 2 lone pairs on oxygen and 3 lone pairs on chlorine.
How to draw the Lewis structure of HOCl
- Count valence electrons: H has 1, O has 6, Cl has 7. Total = 1 + 6 + 7 = 14 electrons.
- Put oxygen in the middle (hydrogen can only form 1 bond, so it must be on an end) and connect H-O and O-Cl with single bonds, using 4 electrons.
- Give chlorine 3 lone pairs to complete its octet (6 electrons), bringing the total used to 10.
- Place the remaining 4 electrons (2 lone pairs) on oxygen, completing its octet: 2 bonds + 2 lone pairs = 4 electron groups, 8 electrons.
Worked example: the bent shape
Oxygen in HOCl has 4 electron groups (2 bonds + 2 lone pairs), which arrange tetrahedrally — but with 2 of those positions taken by lone pairs, the shape traced by the 3 atoms (H, O, Cl) is bent, the same basic shape as water, with an H-O-Cl angle just under 109.5°.
Build HOCl and other molecules atom by atom, and see the bent shape form in 3D, in the Molecule Builder below.
Frequently asked questions
What is the correct order of atoms in HOCl?
H-O-Cl. Oxygen sits in the middle because hydrogen can only form 1 bond and the formula groups O and Cl’s bonding around oxygen, which is the central, less electronegative choice between O and Cl in this molecule.
How many lone pairs are on the oxygen in HOCl?
Two. Oxygen has 6 valence electrons, uses 2 in its bonds to H and Cl, leaving 4 electrons (2 lone pairs).
What is the molecular geometry around the oxygen in HOCl?
Bent. Oxygen has 2 bonds and 2 lone pairs (4 electron groups total), which arrange tetrahedrally, but the shape described by the atoms alone is bent, similar to water.
Is HOCl polar?
Yes. The H-O and O-Cl bonds have different electronegativity differences and the bent shape means their dipoles don’t cancel, giving HOCl an overall dipole.
