Equilibrium in a Syringe—Chemical Demonstration Kit

Product Details

It's bubbly, it's colorful—it's equilibrium in a syringe! Use ordinary seltzer water, an acid–base indicator and a large syringe to transform a common gas solubility phenomenon into an exciting, hands-on demonstration. An acid–base solution is added to the seltzer water and a portion of the solution is drawn into the syringe. Students note the pH by comparison to the indicator color chart. As the temperature and pressure of the solution in the syringe are varied, the solubility of carbon dioxide gas changes. Students observe the equilibrium shifts in the syringe as they monitor the pH of the solution. Enough materials are provided to perform the demonstration seven times. Concepts: Equilibrium, gas solubility, acid-base indicators, LeChatelier's principle. Time Required: 20 minutes Materials Provided: Syringe (140-mL), seltzer water, bromcresol green indicator solution, indicator color chart. Note: The demonstration requires carbon dioxide. A supplemental procedure for generating carbon dioxide is included.