EAMCET Engineering 2010 Solved Paper

(a) Cu+=[Ar]3d10
(No unpaired electrons, so it is colourless)
Zn2+=[Ar]3d10
(No unpaired electrons, so it is colourless)
(b) Cu2+=[Ar]3d9
(One unpaired electron is present, so it is coloured)
Zn2+ is colourless.
(c) The colour of Fe2+ is green while that of Fe3+ is blue.
(d) MnO4−contains no unpaired electrons, however, it is coloured due to charge transfer.
Thus, only statement given in option (a) is correct.