Select correct statement(s).

Options

A. `MnO_(4)^(-)` is intensive pink colour due to d-d electron.
B. `Cu(I)` is diamagnetic while `Cu(II)` is paramagnetic .
C. `CrO_(3)` is amphoteric oxide.
D. `[Ti(H_(2)O)_(6)]^(3+)` and `[Sc(H_(2)O)_(6)]^(3+)` both are coloured in aqueous soloution.

Answer

B

Explanation

(A) coloured due to charge transfer from ligand to metal ion.
(B) Valence shell electron configuration of `Cu(I)` is `3d^(10)` and , therefore , all electron are paired, Valence shell electron configuration of `Cu(II)` is `3d^(9)` and , therefore , one electron is unpaired.
(C ) `CrO_(3)` is an acid anhydried of chromic acid.
(D ) Valence shell electrons configuration of `Ti^(3+)` is `3d^(1)` and , therefore , has one unpaired electron, So it is coloured . But valence shell electron configuration of `Sc^(3+) is `3d^(0)` and , therefore , it has no unpaired electron, so it is colourless.