Observing Changes to Equilibrium Forestville Central School Regents Chemistry

Introduction In this experiment you will be introduced to chemical equilibrium. In this experiment you will be introduced to chemical equilibrium. You will then be presented with a number of systems at equilibrium and will be asked to "stress" these systems by changing the concentration of one of the reactants or products or by changing the temperature of the system. You will then be presented with a number of systems at equilibrium and will be asked to "stress" these systems by changing the concentration of one of the reactants or products or by changing the temperature of the system. Click to Advance

Experiments Complete each one of the experiments below and answer the questions on your worksheet. Click on the pictures to guide you. Complete each one of the experiments below and answer the questions on your worksheet. Click on the pictures to guide you. Cobalt System Ammonium System Iron Thiocyanate System Chromate System Copper Sulfate System

Cobalt System NOTES: - Silver ions react with chloride ions to form the insoluble compound silver chloride. 1) 2) 3) 4) 5) Hint: read the note below CoCl 4 2- Hint: Think about The Cl - ion Click to Return to Experiments Home Page

Cobalt System 1) Answer: 1) Answer: Equilibrium shifts to the left Equilibrium shifts to the left Click to Return

Cobalt System 2) Answer: 2) Answer: Equilibrium shifts to the right Equilibrium shifts to the right Click to Return

Cobalt System 3) Answer: 3) Answer: Equilibrium shifts to the Right Equilibrium shifts to the Right Click to Return

Cobalt System 4) Answer: 4) Answer: Equilibrium shifts to the left Equilibrium shifts to the left Click to Return

Cobalt System 5) Answer: 5) Answer: Equilibrium shifts to the right due to the precipitation out of the Cl - ions in AgCl. Equilibrium shifts to the right due to the precipitation out of the Cl - ions in AgCl. Click to Return

Ammonium System NOTES: - The purplish color is due to phenolphthalein. The darker the purple color, the larger the hydroxide ion concentration in solution. 1) 2) pink Colorless Click to Return to Experiments Home Page

Ammonium System 1) Answer: 1) Answer: Equilibrium shifts to the right (see notes regarding color) Equilibrium shifts to the right (see notes regarding color) Click to Return

Ammonium System 2) Answer: 2) Answer: Increase in temperature shifts the equilibrium to the RIGHT Increase in temperature shifts the equilibrium to the RIGHT Click to Return

Iron Thiocyanate NOTES: - the HPO 4 -2 ion forms a complex with the Fe +3 ion. 1) 2) 3) 4) Click to Return to Experiments Home Page Hint: See notes

1) Answer: 1) Answer: Equilibrium shifts to the Right Equilibrium shifts to the Right Iron Thiocyanate Click to Return

2) Answer: 2) Answer: Equilibrium shifts to the right Equilibrium shifts to the right Iron Thiocyanate Click to Return

3) Answer 3) Answer Equilibrium shifts to the left Equilibrium shifts to the left Iron Thiocyanate Click to Return

4) Answer 4) Answer Due to the removal of Fe +3, equilibrium shifts to the left Due to the removal of Fe +3, equilibrium shifts to the left Iron Thiocyanate Click to Return

Chromate System Na 2 CrO 4 1) Na 2 Cr 2 O 7 Click to Return to Experiments Home Page 2)

Chromate System 1) Answer: 1) Answer: Equilibrium shifts to the right Equilibrium shifts to the right Click to Return

Chromate System 2) Answer: 2) Answer: Equilibrium shifts to the left Equilibrium shifts to the left Click to Return

Copper Sulfate System

Answer: Answer: Equilibrium shifts to the right as water is heated off Equilibrium shifts to the right as water is heated off Copper Sulfate System Question: What if you add water Back to the dish?

Copper Sulfate System Answer: Answer: Equilibrium shifts back to the left as water is added back to the unhydrated crystal Equilibrium shifts back to the left as water is added back to the unhydrated crystal Click to Return to Experiments Home Page