Choose one or more: Draw the Lewis structure. Consider and draw alternate resonance structures. Calculate the molar mass of the compound. Leave out the lone pairs of electrons. Complete the octets of each atom (dublet for H). Determine the central atom, if possible. Determine the number of covalent bonds in the structure. Check the structure with electron bookkeeping   Question: Determine which of the following procedures are steps in drawing the resonance structures of pyridine and pyrazine. Check all that apply.

1. Draw the shapes of the various d orbitals and explain why they are split into two groups; 12g and eg in an octahedral field Draw a diagram to show how the d orbitals are split into groups with different energy in an octahedral field. Some electronic configurations may exist in both high spin and low spin arrangements in an octahedral field. Draw all of these cases, and suggest which metal ions and which ligands might give rise to each. Draw an energy level diagram to show the lifting of degeneracy of the 3d orbitals in a tetrahedral ligand field . Give the number of unpaired electrons in a strong and weak octahedral field for (a) Cr² (b) Co and (c) Fe. Calculate the CFSE and magnetic moment in each case

9. Describe and explain the Jahn teller effect in octahedral complexes of Cu² and Cr Define paramagnetism and diamagnetism. What is the difference between an inner orbital complex and an outer orbital complex? The complex [NiCN)4] is diamagnetic, but [NiCla] is paramagnetic and has two unpaired electrons, explain these observations and deduce the structures of the two complexes The complex ion [Co (NH3)6] is octahedral and diamagnetic, the complexion [CoF6] is also octahedral but paramagnetic. How does valence bond theory account for this observation? How does crystal field explain color of complexes?