Microscale Extraction of Liquid Oxygen from a Cryogenic Mixture Formed through Condensation of Ambient Air

作者：Statler Jeffrey^*

来源：Journal of Chemical Education, 2018, 95(1): 116-120.

DOI：10.1021/acs.jchemed.7b00436

• General Public
• First-Year Undergraduate/General
• Demonstrations
• Misconceptions/Discrepant Events
• Phases/Phase Transitions/Diagrams
• MO Theory
• Magnetic Properties

This demonstration extracts liquid oxygen from a cryogenic mixture collected through condensation using a small neodymium magnet. In a simple and inexpensive procedure, small amounts of liquid oxygen can be safely collected and observed. Students directly witness the collection of this cryogenic mixture over a 30 minute time period and the subsequent immediate removal of small quantities (ca. <1 mL) of liquid oxygen as a consequence of its paramagnetic properties. Several techniques are suggested that allow the efficient handling and display of the magnet used for the extraction. Although framed here in the context of an introductory chemistry or general chemistry course, these procedures can easily be adapted to general-interest audiences or more advanced undergraduate chemistry courses.

• 出版日期2018-1