======Dry ice Rainbow Colors======


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**Materials: **{{$demo.materials_description}}\\
**Difficulty: **{{$demo.difficulty_description}}\\
**Safety: **{{$demo.safety_description}}\\
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**Alternative titles:** Dry Ice Color Show
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====Summary====                   
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====Procedure====  
  - Set out five 1-L beakers filled about three-quarters full with water.  
  - Add 2 mL of a different indicator solution to each beaker (bromcresol green, universal indicator, phenol red, methyl red, bromthymol blue).  
  - Add a small amount of ammonia dropwise to adjust each solution so it starts in its basic color range.  
  - Prepare five smaller beakers (100 mL each) as reference solutions by transferring some liquid from each large beaker.  
  - Wearing insulated gloves, place a nugget of dry ice (about the size of a walnut) into each of the five prepared beakers.  
  - Observe vigorous bubbling, fog formation, and color changes as carbon dioxide dissolves and the solutions shift to acidic colors.




====Links==== 
Dry Ice Color Show - FlinnScientific: 
{{youtube>Hf2bCA1i-Oc?}}\\

Dry Ice Rainbow of Colors - FlinnScientific: 
{{youtube>jZ90oy69QBE?}}\\

📄 Dry Ice Color Show- FlinnScientific: [[https://www.flinnsci.com/api/library/Download/eb185d0fe3b6425094eb97f6546dbcda?srsltid=AfmBOopYnzYwotMoh52ykLgsvbF3rhFBjJidTdKSpgvp2q3HU0mc2y1S]]\\


====Variations====
  * Use different indicators to expand the range of colors demonstrated.  
  * Compare the rate of color change with larger vs. smaller dry ice pieces.  
  * Try the experiment in warm vs. cold water to observe changes in sublimation rate.  




====Safety Precautions====
  * Always wear chemical splash goggles, gloves, and a lab apron.  
  * Handle dry ice with insulated gloves—never touch with bare skin (risk of frostbite).  
  * Work in a well-ventilated area since carbon dioxide gas can accumulate.  
  * Ammonia is irritating; avoid inhalation of fumes.  
  * Dispose of solutions according to lab safety guidelines and allow unused dry ice to sublimate in a ventilated area.  





====Questions to Consider====
  * Why does the solution appear to “boil” when dry ice is added, even though it is not hot?  
  * What chemical reaction occurs when carbon dioxide dissolves in water?  
  * How does the pH change explain the color shifts in the indicators?  
  * How does this demonstration help explain natural processes like ocean acidification?