Question

Below is a 3D representation of a cyclohexane (C6H12) molecule, a cyclic compound used in the manufacture of nylon and found in the distillation of petroleum.

Below is a 3D representation of a cyclohexane (C6H12) molecule, a cyclic compound used in the manufacture of nylon and found in the distillation of petroleum. Name the geometry around each carbon atom. Be sure to rotate the molecule to see all atoms. What is the hybridization of each carbon atom? Click on the box below to activate the module. Then use the toolbar buttons to to rotate the molecule.

Answer 1

Concepts and reason

The geometry of the molecule depends on the electron groups that have maximum separation. The shapes of molecules or ions can be explained based on valence shell electron pair repulsion (VSEPR) model. This model is mainly applicable to p-block elements.

Before overlapping with 1s orbital of hydrogen, first the atomic orbitals of carbon undergoes hybridization to form hybrid orbitals. The hybrid orbitals involve in bond formation with hydrogen.

Fundamentals

The main postulates of VSEPR model is as follows:

(i) The shape of molecule depends on the electron-electron repulsions present in the valence shell of the central atom.

(ii) The repulsive interactions between the electron pairs are in the following order:

${\rm{lone pair - lone pair}} > {\rm{lone pair - bonding pair}} > {\rm{bonding pair - bonding pair}}$

(iii) If the central atom forms multiple bonds, then the order of electron–electron repulsions between them is as follows:

${\rm{triple bond - single bond}} > {\rm{double bond - single bond}} > {\rm{single bond - single bond}}$

The geometrical arrangement of the atoms is molecular geometry.

The geometrical arrangement of the electron groups is electron geometry.

Mixture of one s and three p orbitals is $s{p^3}$ . The geometry of $s{p^3}$ hybridized atom is tetrahedral.

Mixture of one s and two p is $s{p^2}$ . The geometry of $s{p^2}$ hybridized atom is trigonal planar.

Mixture of one s and one p is $sp$ . The geometry of sp hybridized atom is linear.

The structure of cyclohexane is as follows:

The hybridization around each carbon is labelled as follows:

Ans:

Thus, the geometry around each carbon atom in cyclohexane is tetrahedral.

Thus, the hybridization around each carbon atoms is $s{p^3}$ .