Numford
Hybridisation

Hybridisation of H₂S

S is sp³ hybridised (hybridization by the VSEPR count): 2 sigma bonds and 2 lone pairs give a bent shape, bond angle about 92°.

HSH
  • S
  • H
  • lone pair

H₂SHydrogen sulphide

Bent

AB₂E₂: 2 bond pairs, 2 lone pairs

  • Hybridisationsp³
  • Bond angleabout 92°
  • Polaritypolar

Why this shape

  1. S has 6 valence electrons. It uses two in two single bonds to H, so four are left as two lone pairs.
  2. Steric number = two sigma bonds + two lone pairs = 4, so S is sp³ hybridised.
  3. Four electron pairs point to the corners of a tetrahedron (tetrahedral electron geometry). With two lone pairs in place of atoms, the atoms make a bent shape.
  4. S is larger and less electronegative than O, so the bond pairs sit farther from S and repel less. The angle closes to about 92 degrees, much less than 104.5 in water.
  5. The bond dipoles do not cancel in the bent shape, so H₂S is polar.

Lewis structure

8 valence electrons
SHH

Formal charges: none

Working

Why this hybridisation and shape

  1. S has 6 valence electrons. It uses two in two single bonds to H, so four are left as two lone pairs.
  2. Steric number = two sigma bonds + two lone pairs = 4, so S is sp³ hybridised.
  3. Four electron pairs point to the corners of a tetrahedron (tetrahedral electron geometry). With two lone pairs in place of atoms, the atoms make a bent shape.
  4. S is larger and less electronegative than O, so the bond pairs sit farther from S and repel less. The angle closes to about 92 degrees, much less than 104.5 in water.
  5. The bond dipoles do not cancel in the bent shape, so H₂S is polar.

Class 11, Chapter 4 Chemical Bonding and Molecular Structure.

Questions

Hybridisation of H2S: quick answers

What is the hybridisation of H2S?

S has 6 valence electrons. It uses two in two single bonds to H, so four are left as two lone pairs. Steric number = two sigma bonds + two lone pairs = 4, so S is sp³ hybridised.

What is the shape of H2S and its bond angle?

Bent, with a bond angle of about 92 degrees. Four electron pairs point to the corners of a tetrahedron (tetrahedral electron geometry). With two lone pairs in place of atoms, the atoms make a bent shape. S is larger and less electronegative than O, so the bond pairs sit farther from S and repel less. The angle closes to about 92 degrees, much less than 104.5 in water.

Is H2S polar or non-polar?

Polar. The bond dipoles do not cancel in the bent shape, so H₂S is polar.

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