Write the IUPAC name of

Pentaamminenitrocobalt(III)nitrate

While naming co-ordination compounds the ligands should be named first in alphabetical order irrespective of their number, hence first NH₃ is named. 5 NH₃ are present hence pentaammine. One NO₂^- implies nitro. Then the metal is named with its oxidation state, cobalt(III). Oxidation state is 3+ as the charge is neutralized by one nitro and two nitrate ions, all of which are monovalent anions. Finally the nitrate present outside the complex is named. There is no need to mention the number of nitrates in the name.