Evaporation as an Endothermic Process
Description: A flask containing acetone is hooked to an aspirator. As the pressure inside the flask is lowered, the acetone boils and its temperature drops.
Source: Shakhashiri, B.Z. Chemical Demonstrations: A Handbook for Teachers of Chemistry
Year: 1989 Vol: 3 Page: 5
Keywords: Evaporation, Endothermic, Acetone, Boiling, Reduced pressure
Rating: 
Hazard: Medium
- Flammability hazard
- Eye irritation hazard
- Central nervous system toxicity hazard
- Implosion hazard
- Electric shock hazard
Effectiveness: Average
- Secondary observations
- Mild effects are seen by audience
- Results are observable with guidance
- Good connection from demo to course material
- Contrast between systems is noticeable
- Moderate failure rate
- Time to results is medium
Difficulty: Medium
- Use of toxic substances
- Demos at non-standard conditions
- Handling of organic chemicals
- Experiments where data, recording, or display are necessary
- Some intermediate steps to results
Safety Precautions:
- Eye protection required
- Gloves required
- Absorbent material on hand
- Perform in a well-ventilated area
- ABC fire extinguisher on hand
- Boiling beads required in flask
- Use of UL approved three-prong plug and outlet
Class: Intermolecular Forces, Thermodynamics
Division: General, Physical Chemistry
Home| General Chemistry Demos| Physical Chemistry Demos