Among \( \mathrm{Co^{3+}} \), \( \mathrm{Ti^{2+}} \), \( \mathrm{V^{2+}} \) and \( \mathrm{Cr^{2+}} \) ions, one if used as a reagent cannot liberate \( \mathrm{H_2} \) from dilute mineral acid solution, its spin-only magnetic moment is gaseous state is ______ B.M. (Nearest integer)