Question

What is the difference between Carbocation and Carbanion?

Answer 1

Carbocation and Carbanion are two terms that are frequently used in organic chemistry. These are organic chemical species bearing an electrical charge on a carbon atom. These are found as intermediates of some reactions.

Complete answer:
Carbocation is generally defined as an ion in which the central carbon atom is positively charged. A carbocation can have one or more positive charges in its central atom, it is normally unstable because due to the loss of electrons, the $p$ orbitals are free due to loss of electrons. Carbocations are paramagnetic due to incomplete electron pairing. It shows $s{p^2}$ hybridization.
Types of Carbocations:
There are four types of carbocation:
$1.$ Methyl Carbocation- These carbocation contain a positively charged carbon atom that is not attached to any other carbon atoms.

$2.$ Primary Carbocation- The positively charged carbon atom in the carbocation is connected to another carbon atom through a covalent bond. This carbocation is stable than methyl carbocation but is less stable than other Carbocations.

$3.$ Secondary Carbocation- The positively charged carbon atom is bonded to two other carbon atoms. These Carbocations are more stable than primary Carbocations.

$4.$ Tertiary Carbocation- The positively charged carbon atom is attached to three other carbon atoms. This form is very stable.

Carbanion is an ion that contains a negatively charged carbon atom. In this a carbon atom bearing negative charge is $s{p^3}$ hybridized and the geometry is pyramidal. Carbanion is diamagnetic due to completion of electron pairing.
There are four types of carbanion:
$1.$ Methyl Carbanion- The negatively charged carbon atom is not bonded to any other carbon atom.

$2.$ Primary Carbanion- Here the negatively charged carbon atom in the carbanion is connected to another carbon atom through a covalent bond.

$3.$ Secondary Carbanion- The negatively charged carbon atom is bonded to two other carbon atoms.

$4.$ Tertiary Carbanion- The negatively charged carbon atom is attached to three other carbon atoms.

Difference between Carbocation and Carbanion:

Serial number	Carbocation	Carbanion
$1.$	A carbocation is an ion having a central carbon atom which is positively charged	A carbanion is an ion having a central carbon atom which is negatively charged.
$2.$	The carbon atom is $s{p^2}$ hybridized	The carbon atom is $s{p^3}$ hybridized
$3.$	Geometry is trigonal planar	Geometry is Pyramidal
$4.$	Carbocation is paramagnetic	Carbanion is Diamagnetic
$5.$	It act as an electrophile	It act as an nucleophile
$6.$	It is more stabilized due to the presence of three donor methyl groups which donate electrons and therefore greatly stabilize the positive charge.	It is less stabilized.
$7.$	An electron deficient specie	An electron rich species.
$8.$	There are $6$ electron in the outermost shell	There are $8$ electrons in the outermost shell
$9.$	It accepts an electron pair from a nucleophile to produce a covalent bond.	Normally donate an electron pair to an electrophile to produce a covalent bond.

Note:
In various chemical reactions, the carbocation performs as an electrophile; conversely in many chemical reactions, the carbanion acts as a nucleophile.
Carbocation is formed if the organic molecule has a good leaving group, it can leave the molecule through ionization. The ionization gives the bonding electron pairs to the leaving group, resulting in a positive charge on the carbon atom. ${(C{H_3})_2}CH - \mathop O\limits_{ \bullet \bullet }^{ \bullet \bullet } H \to {(C{H_3})_2}C{H^ + } + \mathop {{}_ \bullet ^ \bullet O}\limits_{ \bullet \bullet }^{ \bullet \bullet } {H^ - }$ .