What is the oxidation number of Rh in (PPh3)3RhCl?

The oxidation state of Rhodium (Rh) in the complex (PPh3)3RhCl is +1. This is because each triphenylphosphine ligand (PPh3) contributes -1 charge (-3 total), and the chloride ligand (Cl) contributes -1 charge. Since the overall charge of the complex is neutral, the oxidation state of Rh is +1.