2) Explain why Werner complexes having the same formula [Co(NH3)4Cl2]. But their colors are different? 3) What is the main difference between constitutional and stereoisomers isomers? Give examples 4) Draw the possible isomerism of the complex [Co(NH3)3Cl3]. Precise which isomer is optical active? 5) Precise the shape (geometry) when the coordination number of a central metal is equal 4. 6) Complexes with five d electrons (d5) are sometimes tetrahedral and sometimes octahedral. Consider the high-spin complexes [FeCl4]and [FeCl6]3. Knowing the splitting energy of the octahedral complex =11000cm1, deduce that corresponding to the tetrahedral t(cm1)= ( five significant figures)