Virtual Lab: Types of Reactions—Decomposition (Thermal Decomposition of Sodium Bicarbonate)

The purpose of this video is to demonstrate using laboratory techniques to observe a decomposition reaction. SEE ERRATA before conducting this lab.

ERRATA:
1.) I forgot to wear goggles in the video! Long day!
2.) In the video, I stopped the reaction too soon. Allow the heating process to continue until the volume of gas in the graduated cylinder has increased by about 65 ml. Heating an empty test tube will, due to thermal expansion, increase the volume by about 30 ml.
3.) Don't force the reaction to cool down too quickly. Let the hot test tube and reactant have plenty of time to complete.

Evidence of the reaction is easily seen in the production of gas.

Primary Reaction: 2 NaHCO3 → Na2CO3 + H2O + CO2

Possible Secondary Reaction: Na2CO3 → Na2O + CO2
*** The decomposition of anhydrous sodium carbonate into sodium oxide and carbon dioxide occurs slowly at room temperature and proceeds to completion at 851 C.

Lab Template:
(The template directions reflect the changes suggested in the Errata.)

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NOTICE:

The producer of this video offers it as-is to viewers who are free to use it at their own risk. Errors and omissions are not the responsibility of the producer, nor of anyone associated with its production.

The video and its contents are the sole responsibility and property of Bill Snodgrass. No other party or agency is involved.

Video shot at Lowell High School, Tricreek School Corporation, Lowell, Indiana. Lowell High School, Tricreek School Corporation, Lowell, Indiana and The State of Indiana are not responsible for the production or content of this video.