======Blowing Balloon in Flask======


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**Alternative titles:** Vacuum Balloon Demo
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====Summary====                   
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====Procedure====  
  - Add about 10 mL of water to a 250-mL borosilicate Erlenmeyer flask.  
  - Heat the flask on a hot plate or over a Bunsen burner until the water boils and steam rises.  
  - Remove the flask from the heat and quickly stretch a balloon over the flask opening.  
  - Cool the flask under running cold water or in an ice bath.  
  - Watch as the balloon collapses and gets pushed inside the flask.



====Links==== 
Similar concept: Balloon in a Bottle - Sick Science!: 
{{youtube>yaDVnQOvjfU?}}\\


📄 Balloon in the Flask - Flinn Scientific: [[https://www.flinnsci.com/api/library/Download/e2dfff9fc2324f51889429583a51ac63?srsltid=AfmBOory9enzier6TnB_y-Bn4jaZOAnmPEG1yWe25xmKV4hNn_8QZIna]]\\

====Variations====
  * Put a hole in the flask and suck to 'blow up' the balloon.



====Safety Precautions====
  * Take care when handling hot glass.  
  * Inspect flask for cracks or chips before heating.  
  * Only use borosilicate glass to avoid breakage.  
  * Be careful with steam and hot water to prevent burns.




====Questions to Consider====
  * Why does the balloon get pushed into the flask instead of being “sucked” in? (It is pushed in by greater atmospheric pressure outside compared to the lower pressure inside.)  
  * What role does condensation of steam play in this experiment? (It reduces the internal pressure by creating a partial vacuum.)  
  * How is this similar to the Crush the Can demonstration? (Both rely on pressure differences caused by cooling steam inside a closed container.)  
  * What real-world examples show the effects of atmospheric pressure? (Vacuum-sealed food containers, suction cups, or collapsing oil drums.)