why chloro instead of monochloro

[Haocheng Zhang 2A]

The name of [Pt(NH3)5Cl]Br3 is pentaamminechloroplatinum(IV) bromide. I wonder why we write chloro instead of monochloro.

[Naveed Zaman 1C]

The "-monochloro" is just redundant. This is because whenever we don't add prefixes to a ligand it is assumed that there is only a single one present in the compound. Prefixes are only reserved for showing we have more than 1 of a ligand present in the compound (i.e. di-, tri-, tetra-, etc.).

[Haocheng Zhang 2A]

Also, how to identify a polydentate ligand?

[Alex Nechaev 1I]

Also, how to identify a polydentate ligand?

A polydentate ligand can be recognized by having more than 2 lewis base sites, such as multiple lone pair donating sites used to bond to a central atom or ion.