
A green bead signifies the presence of Fe3+, which possesses 5 unpaired electrons. The spin-only magnetic moment, calculated using the formula \( \mu = \sqrt{n(n + 2)} \, \text{BM} \) with \( n = 5 \), is \( \mu = \sqrt{5(5 + 2)} = \sqrt{35} \approx 5.92 \, \text{BM} \). The nearest integer value is 6.
Kjeldahl's method cannot be used for the estimation of nitrogen in which compound? 
In the group analysis of cations, Ba$^{2+}$ & Ca$^{2+}$ are precipitated respectively as