An Inorganic Green Chemistry Experiment

Recent high-profile developments in the field of Green chemistry, such as the awarding of the 2005 Nobel Prize in Chemistry to Chauvin, Grubbs and Schrock for their development of a green organic-synthesis method, has brought Green chemistry to the forefront and highlighted the need to develop undergraduate programs, which teach the ideals of sustainable chemistry. An inorganic experiment is hereby presented which introduces Green Chemistry but is also correlated to many of the topics covered in the inorganic chemistry curriculum such as the hard/soft acid/base concept, charge density, ionic lattices, thermodynamics and molecular orbital theory. Alkali metal chlorides (MCl2n H2 O; M = Mg, Ca, Sr, Ba) are used to produce oxalate (M(C2 O4 )n H2 O; M=Mg, Ca, Sr, Ba) products through a water-based reaction. The use of Green solvents and methods to minimize waste are introduced as well as the topic of percent atom economy. These oxalates hydrates are characterized by thermogravimetric analysis and infrared spectroscopy and the results discussed in terms of the lecture material. Due to the limited expose levels of Sr and Ba, this experiment also provides a safe means to examine the chemistry of some heavy metals.