In the wet tests for identification of various cations by precipitation, which transition element cation doesn't belong to group IV in qualitative inorganic analysis?

We need to identify which transition element cation does NOT belong to Group IV in qualitative inorganic analysis.

Group IV cations are precipitated by H$$_2$$S in the presence of NH$$_4$$Cl and NH$$_4$$OH (basic medium). This group includes: Co$$^{2+}$$, Ni$$^{2+}$$, Mn$$^{2+}$$, and Zn$$^{2+}$$.

Fe$$^{3+}$$ belongs to Group III, where cations are precipitated by NH$$_4$$OH + NH$$_4$$Cl (as hydroxides). Fe$$^{3+}$$ precipitates as Fe(OH)$$_3$$ (brown precipitate) in Group III.

Among the given options:

- Fe$$^{3+}$$ → Group III (NOT Group IV) ✓

- Zn$$^{2+}$$ → Group IV

- Co$$^{2+}$$ → Group IV

- Ni$$^{2+}$$ → Group IV

The correct answer is Option 1: Fe$$^{3+}$$.