5.311 introduces experimental chemistry for students who are majoring in chemistry. Principles and applications of chemical laboratory techniques, including preparation and analysis of chemical materials, measurement of pH, gas and liquid chromatography, visible-ultraviolet spectrophotometry, infrared spectroscopy, kinetics, data analysis, and elementary synthesis are taught. Students gain experience in these areas by completing the four experiments detailed below.
This is an integrated experiment comprising topics from inorganic, organic, analytical, physical, and computational chemistry. It introduces the student to some of the basics of acquiring data pertaining to the kinetics of a chemical reaction, manipulating data to extract information such as reaction order and rate constants, and how to assess the catalytic effect of the reaction environment upon rate constants.
This experiment is designed to introduce the basic concepts of nuclear magnetic resonance (NMR) spectroscopy - spin, energy levels, absorption of radiation, and several NMR spectral parameters, and to provide experience in identification of unknowns via 1H (proton) NMR spectra. A series of known samples will be used to introduce methods of sample preparation, operation of the NMR spectrometers, and 1H-NMR spectra from which students will measure chemical shifts, J-couplings and spectral intensities. Subsequently, students will record spectra of three unknowns and will use these spectra to determine the structure and identity of the compounds.
This experiment introduces basic manipulative procedures and techniques of preparative chemistry and quantitative volumetric analysis, and provides experience with pH meters. A sample of an alkali or ammonium salt of an unknown aromatic carboxylic acid is converted to the acid, isolated, purified and the yield and melting point determined. Carbonate-free sodium hydroxide solution, which is prepared and standardized against pure potassium acid phthalate, is used to determine the equivalent weight of the purified acid by titration. The apparent pKa of the unknown acid is determined by potentiometric titration with a glass electrode. Finally, a proton NMR spectrum of the acid is recorded and interpreted to verify the proposed structure.
This experiment involves the synthesis of a relatively simple covalent compound. In addition to teaching how to execute a reaction under an inert atmosphere, this experiment also introduces thin-layer chromatography as an analytical tool and column-chromatography as a means of purification.