(a) Write the IUPAC name of the complex $[ ext{Pt}( ext{en})_2 ext{Cl}_2]^{2+}$. Draw the structure of geometrical isomer of this complex which is optically inactive. OR (b) (i) Write the formula of the following coordination compound : Pentaamminecarbonatocobalt(III)chloride (ii) Write the IUPAC name of the linkage isomer of the complex $[ ext{Co}( ext{NH}_3)_5( ext{NO}_2)] ext{Cl}_2$.