Today I finished the solubility unit by working out an example involving fractional/selective precipitation. If you are keeping up with the material, at this point you should be able to handle any of the problems from the solubility set.
The next unit we will discuss is Coordination Chemistry or the Chemistry of Transition Metals. We will discuss the bonding and properties of the complex ions we have been observing in the Qualitative Analysis lab and will give a reason for why Ni(NH3)62+ is blue Co(NH3)62+ is pink, and Zn(NH3)62+ is clear or colorless.
In order to analyze these complexes we must first have a firm grasp of the electron configurations of transition metal ions. When a transition metal forms a cation or a complex, it will ALWAYS lose its s electrons first, then its d electrons. When we detect color with our eyes, complexes absorb photons of visible light. This is due to an electron being excited from one molecular orbital to another. In order to analyze the excitations occurring in transition metal complexes we must first know how many electrons they have. So take a look at the transition metal homework set and start by writing out the proper electron configurations for each cation. You will need to know this information.
We will start Friday's lecture by discussing coordination compounds and we will analyze how they form by looking into the ligands that will attach to them.
Music played before lecture:
I totally blew it today trying to hook up the laptop, which didn't even work. I'll attempt that demo again next week.
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