\(\mu = \sqrt {n(n + 2)} \,\, = \,\,\sqrt {2(2\,\, + \,\,2)} \,\, = \,\,2.82\,\,BM\)
$\mathrm{NO}_2^{-}, \mathrm{SCN}^{-}, \mathrm{C}_2 \mathrm{O}_4^{2-}, \mathrm{NH}_3, \mathrm{CN}^{-}, \mathrm{SO}_4^{2-}, \mathrm{H}_2 \mathrm{O}$.