Of the ions `Ag^(+),Co^(2+)` and `Ti^(4+)` ,which ones will be coloured in aqueous solutions. (Atomic numbers:)
Ag = 47 , Co = 27, Ti = 22)
(b) If each one of the above ionic species is in turn placed in magnetic field, how will it respond and why?

Answer

(a) `CO_(2+)` will be coloured because it contains unpaired electrons. On the other hand ,`Ag^(+)` has completely filled `3d` subshell and `Ti^(4+)` has empty `3d` subshell, therefore , they will be coloureless.
(b) `Co^(2+)` will be attracted by a magnetic field while `Ag^(+)` and `Ti^(4+)` ions will be repelled.