Molecular Geometry & Shapes

Molecular Shape - Linear

-angle of 180°.

- such as acetylene (HC≡CH).

Molecular Shape - Bent

- In chemistry, the term "bent" can be applied to certain molecules to describe their molecular geometry.

- Water (H2O) is an example of a bent molecule, as well as its analogues.

- The bond angle between the two hydrogen atoms is approximately 104.45°.

Molecular Shape - Trigonal Planar

- Trigonal planar is a molecular shape that results when there are three bonds and no lone pairs around the central atom in the molecule. - The pairs are arranged along the central atom's equator, with 120° angles between them.

- The carbonate ion (CO32-) has a trigonal planar geometry.

Molecular Shape - Tetrahedral

- Tetrahedral is a descriptor of the geometry of a molecule in which a central atom forms four bonds which are directed toward the corners of a regular tetrahedron.

Molecular Shape - Trigonal Pyramidal

- Trigonal pyramidal is a molecular shape that results when there are three bonds and one lone pair on the central atom in the molecule.

- Molecules with an tetrahedral electron pair geometries have sp3 hybridization at the central atom.

- Ammonia (NH3) is a trigonal pyramidal molecule.

Molecular Shape - Really Bent

- In chemistry, the term "really bent" can be applied to certain molecules to describe their molecular geometry.

- The bond angle between the two hydrogen atoms is less than 109°.

Molecular Shape - Trigonal Bi-pyramidal

- Trigonal bipyramidal molecular geometry.

- In chemistry a trigonal bipyramid formation is a molecular geometry with one atom at the center and 5 more atoms at the corners of a triangular di-pyramid.

- Example of this molecular geometry are phosphorus pentafluoride (PF5)

Molecular Shape - Octahedral

- In chemistry, octahedral molecular geometry describes the shape of compounds with six atoms or groups of atoms or ligands symmetrically arranged around a central atom, defining the vertices of an octahedron.

- The octahedron has eight faces, hence the prefix octa.

Linear

AB2

Example: N2O Nitrous oxide

Bent

AB2E

Example: O3 - ozone

Trigonal Planar

AB3

Example: NO3 - nitrate ion

Tetrahedral

AB4

Example: NH4+ - ammonium ion

Trigonal Pyramidal

AB3E

Example: PCl3 - phosphorus tri-chloride

Really Bent

AB2E2

Example: OF2 - oxygen di-fluoride

Trigonal Bipyramidal

AB5

Example: AsF5 - Arsenic pentafluoride

Octahedral

AB6

Example: SeF6 - Selenium hexafluoride

Name the Compound

PCl5

Phosphorus Pentachloride; Phosphorus(V) chloride

Name the Compound

NF3

Nitrogen trifluoride

Name the Compound

SeF6

Selenium hexafluoride

Name the Compound

OF2

Oxygen difluoride

Name the Compound

CBr2O

Carbonyl dibromide

Lewis Structure:

Phosphorus Pentachloride

Lewis Structure:

Nitrogen trifluoride

Lewis Structure:

Selenium hexafluoride

Lewis Structure:

Oxygen difluoride

Molecular Shape:

PCl5

AB5

trigonal bipyramidal

non polar molecule

Molecular Shape:

NF3

AB3E

trigonal pyramidal

tetrahedral

polar

Molecular Shape:

SeF6

AB6

octahedral

nonpolar

Molecular Shape:

OF2

AB2E2

bent 109.5 degrees

polar molecule