Coordination Compounds

Cobalt chloride when dissolved in water forms pink colored complex \(\underline{\mathrm{X}}\) which has
octahedral geometry. This solution on treating with conc \(\mathrm{HCl}\) forms deep blue complex, \(\underline{\mathrm{Y}}\) which has a \(\underline{\mathrm{Z}}\) geometry. \(\mathrm{X}, \mathrm{Y}\) and \(\mathrm{Z}\), respectively, are