Skip to content
ScienceQuest

Ethane (C₂H₆) Lewis structure

14 valence electrons, tetrahedral

C C H H H H H H
C₂H₆ as the Lewis Structure Generator draws it: lone pairs as dots.

Build C₂H₆ step by step in the Lewis Structure Generator

What is the Lewis structure of C₂H₆?

Ethane, C₂H₆, has 14 valence electrons. The two C atoms bond to each other, and the molecule has one C−C single bond and six C−H single bonds. It carries no lone pairs. Every formal charge is zero. Each C is AX₄: tetrahedral, with an ideal bond angle of 109.5°, and the molecule is nonpolar.

Valence electrons in C₂H₆

Element Group Valence electrons Atoms Electrons
Carbon 14 4 2 8
Hydrogen 1 1 6 6
Total 14

In one line: 2 × 4 + 6 × 1 = 14. Each atom brings the valence electrons its group gives it.

How to draw the C₂H₆ Lewis structure

  1. Count the valence electrons. Valence electrons: each C 4 and each H 1. 2 × 4 + 6 × 1 = 14.
  2. Bond the two central atoms. C appears twice, so the two C atoms bond to each other and share the H atoms evenly between them.
  3. Join the atoms with single bonds. Seven single bonds use 14 electrons, leaving 14 − 14 = 0.
  4. Complete the outer atoms. Every outer atom is H, and its one bond already gives it the two electrons it holds. 0 remain.
  5. Put the rest on the central atom. Nothing is left, so each C gets no lone pair, and each C now has 8 electrons round it.
  6. Make multiple bonds where needed. Every atom already has an octet, so no lone pair needs to become a bond.

Lone pairs and formal charges in C₂H₆

Atom Number Bonds Lone pairs Electrons round it Formal charge, V − N − B/2
C (central) 2 four single bonds 0 8 4 − 0 − 4 = 0
H 6 one single bond 0 2 1 − 0 − 1 = 0

V is the atom’s valence electrons, N its nonbonding electrons and B its bonding electrons. The formal charges add up to 0, the molecule’s overall charge.

Shape and polarity of C₂H₆

Central atoms each C
VSEPR class AX₄
Electron geometry tetrahedral
Molecular geometry tetrahedral
Ideal bond angle 109.5°
Polarity, an estimate nonpolar

The two halves are identical and point opposite ways, so their bond dipoles cancel.

Each C has four σ bonds and no lone pairs, four electron domains in all, so its electron geometry is tetrahedral. With no lone pairs, the molecular geometry is the same.

The VSEPR Molecular Geometry viewer turns the AX₄ shape in 3D, lone pairs included.

Work with C₂H₆