Please help me understand this one. Thanks Challenge question: This question is
ID: 474070 • Letter: P
Question
Please help me understand this one. Thanks
Challenge question: This question is worth 6 points. As you saw in problem 9 we can have species bound to a central metal ion. These species are called ligands. In the past we have assumed all the d orbitals in some species are degenerate; however, they often are not. Sometimes the ligands bound to a central metal cation can split the d orbitals. That is, some of the d orbitals will be at a lower energy state than others. Ligands that have the ability to cause this splitting are called strong field ligands, CN^- is an example of these. If this splitting in the d orbitals is great enough electrons will fill low lying orbitals, pairing with other electrons in a given orbital, before filling higher energy orbitals. In question 7 we had Fe^2+, furthermore we found that there were a certain number (non-zero) of unpaired electrons. Consider now Fe(CN)_6^4-: here we also have Fe^2+, but in this case all the electrons are paired, yielding a diamagnetic species. How can you explain this? All the d orbitals are degenerate. There is 1 low lying d orbital, which will be filled with two electrons before filling the 4, assumed to be degenerate, higher energy orbitals. There are 2 low lying d orbitals, which will be filled with 4 electrons before filling the 3, assumed to be degenerate, higher energy orbitals. There are 3 low lying d orbitals, which will be filled with 6 electrons before filling the 2, assumed to be degenerate, higher energy orbitals. There are 4 low lying d orbitals, which will be filled with 8 electrons before filling the 1 higher energy orbital.Explanation / Answer
10. A strong field ligand like CN- would cause pairing of electrons and thus the complex formed from it would be low spin, that is less number or of unpaired electrons in the central metal atom remained.
Fe2+ has a valence configuration of 3d6. The complex has a charge of 4-.
the complex is diamagnetic in nature because,
D) There are 3 low lying degrenerate orbitals, which will be filled first with 6 electrons before filling the 2, assumed to be degrenerate, higher energy orbitals