Experiment 3: Effects Of Changing Conc Or Temp On Equilibrium Position

Question 1

A spectrophotometer can only measure the absorbance of very dilute solutions. Suggest what you would do to determine absorbance of a concentrated solution of Cr^3+.

Answer 1

• the solution must be diluted by adding distilled water
• a certain ration calculation of volume and concentration can be observed through a spectrophotometer —>
  For a concentration of 0,04mol/L; v=100ml:
  80 ml of 0,05mol/L will be used and thus diluted with 20ml of water for a 0,04mol^-1 concentration
• when the concentrated solution of Cr^3+ is diluted, Beer’s Law will be applicable:
  A= Ęcl