Determining K of the Iron thiocyanate equilibrium.

To determine the equilibrium constant using colorimetry for the iron thiocyanate complex equilibrium we must first determine the absorbance of different concentrations iron thiocyanate concentrations. We can then perform a reaction between 0.002mol/L iron nitrate and and 0.002 mol/L potassium thiocyanate and determine the concentration of the iron cyanate present after equilibrium has been established. From this we can use the ice box method to calculate the concentration of all species at equilibrium substitute these values into the equilibrium expression and determine K. Happy days. PS sorry about the lack of story line it was a somewhat last minute thought to film this. Please note, when I was calculating my final K value using the equilibrium constant I used initial concentrations of 0.002 but I was too hasty. I should have used half this value for each as I added 15mL of 0.002 Fe3+ to to 15mL of SCN- thus halving my concentrations initially. This changes the equilibrium constant to be somewhere around 300 I think as oppose to 70 which I calculate in the video.