**Hybridization of SCN-**

The hybridization of SCN- (thiocyanate ion) can be determined by examining the arrangement of its atoms and the types of orbitals involved in bonding. To understand the hybridization of SCN-, let's start by examining the Lewis structure and molecular geometry of the ion.

**Lewis Structure of SCN-**
The Lewis structure of SCN- can be represented as follows:

S = central atom
C = carbon atom
N = nitrogen atom

S
|
C ≡ N

In the Lewis structure, the sulfur atom (S) is bonded to a carbon atom (C) through a single bond, and the carbon atom is further bonded to a nitrogen atom (N) through a triple bond. The overall charge of the SCN- ion is -1, indicating that it has gained an extra electron.

**Valence Electron Calculation**
To determine the hybridization of SCN-, we need to calculate the total number of valence electrons present in the molecule. The sulfur atom contributes six valence electrons, the carbon atom contributes four valence electrons, and the nitrogen atom contributes five valence electrons. Additionally, the negative charge adds one valence electron. Hence, the total number of valence electrons is 16.

**Molecular Geometry and Hybridization**
The molecular geometry of SCN- can be determined by analyzing the arrangement of electron pairs around the central atom. In this case, the sulfur atom is the central atom. The carbon and nitrogen atoms are bonded to the sulfur atom, resulting in a linear molecular geometry.

The linear molecular geometry suggests that the sulfur atom is sp hybridized. The "s" orbital and one "p" orbital of the sulfur atom undergo hybridization to form two sp hybrid orbitals. These orbitals are oriented in a linear arrangement, allowing the sulfur atom to bond with the carbon and nitrogen atoms.

The carbon and nitrogen atoms are both sp hybridized as well. The carbon atom forms one sigma bond with the sulfur atom using its sp hybrid orbital, while the nitrogen atom forms one sigma bond and one pi bond with the sulfur atom using its sp hybrid orbital.

**Conclusion**
In summary, the hybridization of SCN- is as follows:
- The sulfur atom is sp hybridized.
- The carbon atom is sp hybridized.
- The nitrogen atom is sp hybridized.

These hybrid orbitals allow the atoms to form sigma and pi bonds, resulting in the linear molecular geometry of SCN-.

Sp hybridisation. as Carbon is the central atom. and the structure is S=C=N- and the negative sign is the part of nitrogen only so is not considered while determining the hybridization. so the hybridization of scn- is sp