Let me give an example, we had a complex that reflected violet. It said to find the energy absorbed by the complex. It absorbs yellow because it is on the opposite side of the color wheel. Yellow is between 560-600nm. However, anyone who didn't use 580nm to find the energy of the crystal field split got the question wrong, even though yellow spans between those 40nm range.
Second question, there is one asking if it takes less energy to go to a different type of d orbital, for one coordination complex K4[FeCN6] or something and the other one is K3[FeCN6]. So...I interpret this as going from Dxy to Dyz or something (this is crystal field theory question) as opposed to one going from Dyz to Dz^2. The CN is a strong field ligand, so the pairing energy is less than the crystal field split. On one of them, the bottom 3 orbitals were completely filled, and the top were empty. On the other one, the bottom 3 were full except 1 spot. So I said to myself it would take more energy for the electron to jump to the next level than for it to pair up, so I said the complex that paired up would be the right answer since P < Δ. However, his idea of a d-orbital was the 1st bottom 3 being a type of d-orbital, when the top 2 were another type.
The word of interest here is ''type'' of d orbital, and I tried to argue that every box is a different type of d orbital (Dxy, Dyz, Dxy on the bottom and Dz^2 and Dx^2-y^2 on the top) which I think is fine, but he tried to claim the whole row is a type of d orbital.
When I say challenging, his words are ''with what I presented to you in class, you would not be able to answer this question''. Nor is it in the book. It was a multiple choice for these parts, so people could have just been lucky with their selection. The above was free response
I honestly think it's just an issue that my professor is not a native english speaker, so his questions can be worded the way he talks.