Amongest TiF^2+ 6 , CoF^3- 6 , Cu2Cl2 and NiCl^2- 4 (At. nos. Ti = 22 Co = 27 Cu = 29 Ni = 28), the colourless species are

Question

Amongest \(TiF_6 ^{2+} ,CoF_6 ^{3-} , Cu_2 Cl_2\) and \(NiCl ^{2-}_4\) (At. nos. Ti = 22 Co = 27 Cu = 29 Ni = 28), the colourless species are

(a) \(Ti F_6 ^{2-}\) and \(Cu _2Cl_2\)

(b) \(Cu_2 Cl_2 \) and \(NiCl_4 ^{2-}\)

(c) \(TiF_6 ^{2-}\) and \(Co F _6 ^{3-}\)

(d) \(CoF _6 ^{3-}\) and \(NiCl _4 ^{2-}\)

Answer 1

Correct option is (a) \(Ti F_6 ^{2-}\) and \(Cu _2Cl_2\)

The colourless species are \(Ti F_6 ^{2-}\) and \(Cu _2Cl_2\)

Cu₂cl₂ is 2(CuCl) and hence is diamagnetic. So it is colourless.

Ti in \(TiF^{2-} _6\) has no d electrons, so no colour as no d−d transition takes place.