In this set of three demonstrations, students will observe a series of dramatic changes when common ions are added to solutions at equilibrium. The results illustrate the nature of equilibrium and LeChâtelier's principle.
• Adding strong and weak acid solutions to cylinders containing a white powder causes the cylinders to overflow with colorful foam.
• Blowing bubbles into a blue solution changes the color of the solution to yellow. Stirring in a white powder causes the solution to revert back to blue. Blowing again into the solution returns the original yellow.
• Adding a clear liquid to a yellow solution produces an orange mixture. Stir in a white powder and the yellow reappears. Repeating the procedure sets up a color oscillation.
Includes Teacher Demonstration Notes and enough materials to perform each demonstration seven times.
Concepts: Common ion effect, equilibrium, LeChâtelier's principle.
Time Required: 20 minutes
Chemicals Provided: Hydrochloric acid, acetic acid, sodium acetate, sodium chloride, sodium bicarbonate, sodium carbonate, ammonium hydroxide, ammonium chloride, phenolphthalein solution, bromthymol blue solution, alizarin yellow R solution.
Additional ResourcesNo Additional Resources at the time.
Flinn Catalog/Reference Manual Page 360
You May Also Like
- Demonstration Tray, Large
- Beakers, Borosilicate Glass, 1000-mL
- Hydrometer Cylinder, Glass
- Cylinder, Borosilicate Glass, 100 mL
- Equilibrium in a Syringe - Chemical Demonstration Kit
- Exploring Equilibrium: It Works Both Ways - Student Laboratory Kit
- Hot and Cold Equilibrium - LeCh,telier’s Principle - Chemical Demonstration Kit
- Gas Phase Equilibrium - Student Laboratory Kit
- Pink and Blue - A Colorful Chemical Balancing Act - Chemical Demonstration Kit
- Restoring Balance - LeChâtelier's Principle and Equilibrium - Student Laboratory Kit