Equilibrium Changes

Qualitatively Investigating Changes in Equilibrium

Research Topic:

In this lab we will be observing the qualitative changes in equilibrium by changing known concentrations of reactants: iron and thiocyanate ions, and finding its effect on the position of equilibrium. We will be using a colorimeter to find the absorbance of the solutions with known concentrations and we will plot a graph of absorbency vs. concentration which will allow us to quantitatively track the changes in equilibrium of a solution. I will be using iron nitrate and potassium thiocyanate in order to give us ironthiocyanate.

Fe3+(aq) + SCN-(aq) FeSCN2+

Variables Chart

Apparatus:

1 colorimeter
20 ml solution Fe(NO3)3
20 ml solution KSCN
10 ml distilled water
4 test tubes
1 test tube rack

Procedure:

Part 1

Wash a plastic cuvette
Fill it with clean water, as this will be a reference point of absorbance for the colorimeter and measure the absorbance. Since it is clear it should be 0.

Part 2