The salt $NiCl X_{2} \cdot 6 NH X_{3}$ gives 2 mol of $AgCl$ per mole with excess $AgNO X_{3}$ . Assuming octahedral coordination (coordination number 6) and using the spin-only formula, the magnetic moment of the complex ion in BM is

Answer: B

Two free chlorides and coordination number 6 give

[Ni (NH X_{3}) X_{6}] Cl X_{2}

with Ni(II),

d^{8}

. In an octahedral field

d^{8}

t_{2 g}^{6} e_{g}^{2}

whatever the field strength, so 2 unpaired electrons.

μ = n (n + 2) = 8 = 2.83

BM.