Vapor Pressure of Pure Liquids
Description: Video of small amounts of various pure liquids being injected into mercury barometers. The drop in mercury level is equal to the vapor pressure of the liquid. Different pairs of pure liquids, including water and ethanol, butanol and ether, and chloromethane and dichloromethane are compared and the vapor pressure is related to intramolecular forces.
This demonstration is also available on JCE Software “Chemistry Comes Alive!” Vol. 2 CD-Rom
Source: JCE CD-Rom “Chemistry Comes Alive!”
Keywords: Mercury barometers, Vapor pressure, Water, Ethanol, Butanol, Ether, Chloromethane, Dichloromethane
Rating: 
Hazard: High
- Inhalation hazard
- Toxicity: target organ – nervous system
- Reproductive toxicity
- Aquatic toxicity hazard
- Flammability hazard
Effectiveness: Average
- Results observable with guidance
- Noticeable contrast between behavior of systems
- Mild effects are seen by audience
- Time to results is low
- Moderate reliability
Difficulty: High
- Use of sharps
- Injection of chemicals
- Reactions involving toxic or explosive chemicals
- Multi-step procedures with varying results
Safety Precautions:
- Eye protection required
- Gloves required
- No open flames
- Sharps container
- Sharps protection
- Perform in well-ventilated area
- Downdraft hood recommended
- Mercury spill kit required
- Chemical spill kit on hand
- Lab coat required
- Chemical apron required
- Prevent release of reagents to the environment
- Avoid exposure to droplets, mists or vapors
- This demonstration is available as a movie file
Class: Intermolecular Forces, Liquids and Solids, Equilibrium of Chemical Systems
Division: General, Physical Chemistry
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