question_answer

Which of the following sets has all the coloured ions?

A)  \[C{{u}^{+}},C{{u}^{2+}},N{{i}^{2+}}\]

B)  \[C{{u}^{2+}},C{{o}^{2+}},S{{c}^{3+}}\]

C)  \[C{{u}^{2+}},F{{e}^{2+}},C{{o}^{2+}}\]

D)  \[N{{a}^{+}},M{{g}^{2+}},A{{l}^{3+}}\]

Correct Answer: C

Solution :

                Species having unpaired electrons in d-orbitals, allow d-d transition, hence are coloured. Hence, \[C{{u}^{2+}},F{{e}^{2+}}\]and \[C{{o}^{2+}}\] constitute a set of coloured ions.