Question

Choose the complex which is paramagnetic
(i) $[Fe (H_2O)_6]^{2+}\,\,$ (ii) $K_3 [Cr(CN)_6]$
(iii) $K_3[Fe(CN)_6]$ (iv) $K_2 [Ni(CN)_4]$

• A. (i) , (ii) and (iii)
• B. (i), (iii) and (iv)
• C. (ii), (iii), and (iv)
• D. (i), (ii) and (iv)

Answer 1

Answer: (A)

(i) $[Fe (H_2O)_6]^{2+}$
(ii) $[Cr(CN)_6]^{3-}$
(iii) $[Fe(CN)_6]^{3-}$
(iv) $[Ni(CN)_4]^{2-}$
Thus complexes (i), (ii) and (iii) are paramagnetic species.