HCl Lewis Structure
Hydrogen chloride (hydrochloric acid) · A gas that dissolves in water to give hydrochloric acid.
The HCl Lewis structure has 8 valence electrons, drawn as one bond to hydrogen, with three lone pairs in total. The central Cl is sp3 hybridized and the molecule is linear. HCl is polar: the atoms around the centre are not all the same, so the bond dipoles are different sizes and cannot cancel.
- 8 valence e−
- linear
- sp3
- polar
Calculated properties
| Total valence electrons | 8 |
|---|---|
| Bonding electrons | 2 (1 shared pairs) |
| Nonbonding electrons | 6 (3 lone pairs) |
| Electron domains (steric number) | 4 |
| VSEPR notation | AX1E3 |
| Electron geometry | tetrahedral |
| Molecular geometry | linear |
| Bond angle | no angle (only two atoms) |
| Hybridization | sp3 |
| Polarity | polar |
| Formal charges | all zero |
| Resonance structures | none |
| Molar mass | 36.458 g/mol |
How to draw the HCl Lewis structure
-
Count the valence electrons
Add up the outer-shell electrons every atom brings. That total is the budget for the whole structure - every line and every dot has to come out of it, and nothing may be added.
1 (H) + 7 (Cl) = 8 valence electrons -
Work out what is bonded to what
Two atoms, one connection. The only question is the bond order.
-
Join everything with single bonds first
Every connection starts as one shared pair. Draw them all before worrying about double bonds - the arithmetic in the next step is what tells you where the double bonds have to go.
1 bond x 2 = 2 electrons used, 6 left -
Work out how far short you are
Add up what every atom still needs to fill its shell - eight electrons for most atoms, two for hydrogen - minus what its single bonds already give it. Compare that with the electrons you have left. The difference decides everything that follows.
needs 6, has 6, exactly enough -
Fill in the lone pairs
Every electron not in a bond sits as a lone pair on an atom. Each atom takes exactly what it needs to finish its shell - there is no choice left at this point.
Cl: 3 (6 electrons) -
Check the formal charges
Formal charge is valence electrons, minus lone-pair electrons, minus the number of bonds. Every atom here comes out at zero, which is the sign of a good structure.
all formal charges = 0 -
Work out the shape
Count the electron domains on Cl: 1 bonded group plus 3 lone pairs. A double or triple bond still counts as one domain, because it points in one direction. That gives tetrahedral electron geometry; ignore the lone pairs and the atoms themselves sit in a linear arrangement. Two atoms can only lie in a straight line, so there is no bond angle to measure.
steric number 4 -> sp3 -> linear -
Decide whether it is polar
The atoms around the centre are not all the same, so the bond dipoles are different sizes and cannot cancel.
dipoles do not cancel -> polar
Is HCl polar or nonpolar?
HCl is polar. The atoms around the centre are not all the same, so the bond dipoles are different sizes and cannot cancel.
| Bond | Electronegativity difference | Character |
|---|---|---|
| Cl–H | 0.96 | polar covalent |
Common questions
How many valence electrons does HCl have?
HCl has 8 valence electrons. 2 of them are in bonds and 6 sit in lone pairs.
What is the molecular geometry of HCl?
HCl is a linear molecule. The central Cl has 1 bonded group and three lone pairs, a steric number of 4, which gives tetrahedral electron geometry and a linear molecule.
What is the hybridization of HCl?
The central Cl in HCl is sp3 hybridized. Steric number 4 means 4 orbitals have to be mixed, which is exactly what sp3 gives you.
Is HCl polar or nonpolar?
HCl is polar. The atoms around the centre are not all the same, so the bond dipoles are different sizes and cannot cancel.