Question

Select the coloured and paramagnetic ions

• A. $ C{{u}^{+}},Z{{n}^{2+}},C{{a}^{2+}} $
• B. $ S{{c}^{3+}},T{{i}^{4+}},{{V}^{5+}} $
• C. $ C{{u}^{2+}},C{{r}^{+}},M{{n}^{2+}} $
• D. $ N{{i}^{2+}},C{{u}^{+}},H{{g}^{2+}} $

Answer 1

Answer: (C)

Ion is coloured if there are electrons in d-suborbit. Paramagnetic nature is also due to unpaired electrons. Thus, every coloured ion is also paramagnetic.
$ C{{u}^{2+}}=[Ar]3{{d}^{9}}, $
one unpaired electron in 3d.
$ C{{r}^{+}}=[Ar]3{{d}^{5}}; $ five unpaired electrons in 3d.
$ M{{n}^{2+}}=[Ar]3{{d}^{5}} $ five unpaired electrons in 3d.