Geometrical Isomerism in [RhCl(CO)(PPh3)(NH3)]:
Geometrical isomerism occurs when there is restricted rotation around a bond due to the presence of bulky groups or a rigid structure in a molecule. In the complex [RhCl(CO)(PPh3)(NH3)], there are three different ligands - Cl, CO, PPh3, and NH3, which can give rise to geometrical isomers.

Identification of Geometrical Isomers:
- In this complex, the Cl, CO, and PPh3 ligands are all different, allowing for geometrical isomerism to occur.
- The NH3 ligand is considered a non-labile ligand and is not involved in geometrical isomerism.

Number of Geometrical Isomers:
- For a complex with four different ligands, the maximum number of geometrical isomers is 2^n, where n is the number of different ligands.
- In this case, n = 3 (Cl, CO, PPh3).
- Therefore, the total number of geometrical isomers for the complex [RhCl(CO)(PPh3)(NH3)] is 2^3 = 8.
- However, not all of these isomers are unique due to symmetry considerations.

Unique Geometrical Isomers:
- Upon further analysis, it is determined that there are only 3 unique geometrical isomers for the given complex.
- These isomers arise from the different possible arrangements of the Cl, CO, and PPh3 ligands around the central Rh atom.
Therefore, the total number of geometrical isomers for the complex [RhCl(CO)(PPh3)(NH3)] is 3.