Disturbing Equilibruim

Experiment 36
Disturbing Equilibrium

Aim: To observe the effect of a change in conditions on a system at equilibrium and explain the effects observed through Le Châtelier’s principle.

Equipment:
5 medium test tubes
1 test-tube rack
1 100-mL beaker
1 250mL beaker
1 dropper pipet
1 spatula
1 50-mL graduated cylinder
1 white card, to record

Materials:
Saturated potassium nitrate solution, KNO3
0.1 M Iron (III) chloride, FeCl3
0.1 M Potassium thiocyanate, KSCN
Potassium chloride crystals, KCl
Potassium nitrate crystals, KNO3
Ice
Distilled water

Procedure:
Part A. Effect of Temperature on a Physical Equilibrium
1. Add 2- 3 mL of saturated potassium nitrate solution to a clean test tube. Using a spatula, add one crystal of potassium nitrate to the solution to act as a seed crystal.
2. Cool the test tube in a 250mL beaker of ice for 10 minutes. Record results.
3. Remove the test tube from the ice water and place it in the test-tube rack. Record what h...