Topic #5: Procedure

• Effect of Concentration on the Equilibrium

  1. Add one drop each of 0.5 M Fe(NO3)3 and 0.5 M KSCN to 10 mL of distilled water.
• Effect of Concentration on the Equilibrium

  2. Mix well
• Effect of Concentration on the Equilibrium

  3. Add a few drops of this solution to each of five wells of a spot plate.
• Effect of Concentration on the Equilibrium

  4. One well serves as a color standard against which to judge color changes in the other wells.
• Effect of Temperature Change on the Equilibrium

  1. Pour about 4-5 mL of the iron-thiocyanate solution made above into three test tubes.
• Effect of Temperature Change on the Equilibrium

  2. Set one tube aside as a color standard against which to judge color changes in the other tubes.
• Effect of Temperature Change on the Equilibrium

  3. Gently warm the second tube in a hot water bath on a hot plate.
• Effect of Temperature Change on the Equilibrium

  4. Do not boil the solution and observe.
• Effect of Temperature Change on the Equilibrium

  5. Cool the third tube in a beaker of ice water and

  observe.
• Effect of Pressure Change on Equilibrium

  1. Place 5 mL of water to 2 test tubes and add 3 drops of bromothymol blue indicator and 1 mL saturated solution of NaHCO3.
• Effect of Pressure Change on Equilibrium

  2. Add 3 M HCl dropwise util bubbling starts.
• Effect of Pressure Change on Equilibrium

  3. Cover with cork stopper on of the test tube and leave the other test tube open and compare the color change.