Testing for CO2 (Carbon dioxide) with Limewater

Testing for CO2 (Carbon dioxide) with Limewater

Testing for Carbon Dioxide Gas with Lime Water

Introduction to the Experiment

  • The experiment demonstrates how to test for carbon dioxide (CO2) gas by bubbling it through lime water, which is a solution of calcium hydroxide (Ca(OH)₂).
  • The speaker uses a tube to breathe into the lime water, initiating the reaction between CO2 and calcium hydroxide.

Chemical Reaction Overview

  • The reaction involves carbon dioxide reacting with calcium hydroxide to produce solid calcium carbonate (CaCO₃), which appears as a milky white precipitate.
  • Initially, the lime water is clear; however, as CO2 reacts, it transforms into a milky white color due to the formation of calcium carbonate.

Observing Results

  • The presence of the milky white precipitate indicates a successful test for carbon dioxide gas.
  • At this point in the experiment, it can be definitively stated that CO2 has been detected due to the observable change in color and formation of solid.

Conclusion

Video description

To test of the presence of Carbon dioxide (CO2 in a gas) we can bubble it through a solution of limewater. If there is CO2 present it will react with the limewater to produce a milky white precipitate. The reaction is: CO2 (g) + Ca(OH)2 (aq) = CaCO3 (s) + H2O (l) In the products we have CaCO3 (s). That is the precipitate and that is want causes the solution to have the milky white color. Bubbling a gas through limewater is a common lab or demonstration in school to test for the presence of CO2. It also comes up frequently on quizzes and exams! Related videos: How to balance CO2 + Ca(OH)2 : https://youtu.be/j74g0HIOvKI Net ionic equation for: https://youtu.be/rzCzLOCKOYk CO2 + H2O: https://youtu.be/PJ2Lv_GKazY To recap, the limewater test is a useful tool to detect Carbon dioxide. More chemistry at www.Breslyn.org