The number of group reagents used for (V) group basic radicals is.

the reagent of group V cations is (NH₄)₂CO₃ in the presence of NH₄Cl and NH₄OH
It should be noted that the cations of group V are precipitated in the form of carbonates by adding (NH₄)₂CO₃ solution to their hot ammoniacal solution in presence of a little NH₄Cl. The addition of NH₄Cl is mandatory but if it is present in excess amount , the precipitation of group V cations is not complete