Question

How do I know if a molecule will have hybridized orbitals. And how do i know if a molecule will have pi and sigma bonds.

Answer 1

How do I know if a molecule will have hybridized orbitals?

If a central atom of any molecule bonded with more than one atom then it has to be hybridized. Lower energy molecule does not have hybridization and it determines according to VSEPR theory. The hybridization depends upon the molecular geometry like sp3 hybridized molecules have tetrahedral electron geometry, sp hybridized molecules have linear geometry, sp3d hybridized molecules have trigonal bipyramidal electron geometry.

How do i know if a molecule will have pi and sigma bonds?

It can be known by imagining the bonding pattern of the molecule. If the molecule formed by simple sharing of electrons then it will have covalent bond and sigma and pi bonds are types of covalent bond. So if a molecule have covalent bonds then there must be sigma may be one or more than one. The presence of unsaturation or double and triple bond indicates the nature of bond. Both double and triple bod contains pi bond precisely double bond contains one and triple bond contain two pi bonds.

Most of the organic molecule or carbon containg molecules have these covalent bonds (there are few exception like CCl4)