In which of the following pairs are both the ions coloured in aqueous solution?
(a) Ni2+, Ti3+ (b) Sc3+, Ti3+
(c) Sc3+, Co2+ (d) Ni2+, Cu+
(At. no : Sc =21, Ti = 22, Ni = 28, Cu = 29, Co = 27)
Concept Videos :-
Concept Questions :-
(a) 28Ni = 1s2, 2s22p6, 3s23p63d8, 4s2
Ni2+ = 1s2, 2s22p6, 3s23p63d8
22Ti = 1s2, 2s22p6, 3s23p63d2, 4s2
Ti3+ = 1s2, 2s22p6, 3s23p63d1
21Sc = 1s2, 2s22p6, 3s23p63d1, 4s2
Sc3+ = 1s2, 2s22p6, 3s23p6
(unpaired electron in d-orbital is not possible)
29Cu = 1s2, 2s22p6, 3s23p63d10, 4s1
Cu+ = 1s2, 2s22p6, 3s23p63d10
Hence, in above ions, Ni2+ and Ti3+ ions are coloured ions in aqueous solution due to presence of unpaired electrons in d-subshell.