[torturedillini]

I'm trying to determine the molar mass of my cobalt complex unknown. In the procedure, it says to convert my complex to the Co(SCN)4 ion. I don't understand what purpose this serves. 

Why couldn't I just take my unknown, dissolve it in deionized water and determine the absorbance at the wavelength?

I also have a known that is [Co(NH3)5 Cl]Cl2 and I had to convert that to the Co(SCN)4 ion too. I have all the data. I just need this for my discussion.