Chemistry Laboratory Experience
Freshman Cooper Union engineering students are introduced to fundamental concepts in the field of analytical chemistry through the freshman chemistry laboratory course, Ch 111. Analytical chemistry typically involves the determination of the identity and amount of something, called an analyte. This determination often involves learning how to obtain a sample, and then using chemistry to modify the sample so that one can obtain a measurable property that can be used to identify and quantitate its components.The field of analytical chemistry involves either âclassicalâ or âinstrumentalâ methods, and sometimes, a combination of the two approaches. In classical methods, the mass and volume of various solutions are used for analyzing the sample. Classical methods of analytical chemistry typically involve volumetric or gravimetric analysis, like titrations, or precipitation reactions. Instrumental methods involve learning how to use various instruments to determine the identity and concentration of a substance that is surrounded by some kind of matrix. This involves determining the best instrumental method, obtaining a sample, calibrating the instrumental response to the concentration of the analyte, and assessing the reliability of the measurements (how the sample relates to the whole population, error analysis, etc.).
General chemistry laboratory introduces engineering students to both classical and instrumental methods of chemical analysis. Examples of classical methods are one lab experiment that involves determining the amount of chloride in an unknown sample by chemically modifying it and using the analytical balance to determine its mass, while another experiment introduces students to volumetric titrations.
For instrumental methods, students also use a spectrophotometer to determine the physical properties and identity of an unknown weak acid. A spectrophotometer is a very sensitive instrument that uses light to analyze unknowns. A simple way to view this is that if an analyte makes a solution blue, then more of that substance will make the solution a darker shade of blue. Spectrophotometry refers to the quantitative measurement of elements, compounds, or materials as a function of the wavelength of light that they absorb or emit. In this course, the information that the spectrophotometer yields about chemical equilibria is combined with pH information to determine the identity of an unknown weak acid. Another instrumental experiment provides an introduction to the field of electrochemistry, which is important in the development of better batteries, fuel cells, biological sensors, catalysts, and coatings for corrosion prevention. Electrochemical methods are widely used in analytical chemistry because of their great specificity and sensitivity to a wide variety of analytes. Freshman are introduced to the electrochemical concepts through an experiment that involves electroplating copper onto a metal surface and then comparing the information obtained from the electrochemical charge to the mass measurement obtained via the analytical balance.
Freshman engineers are introduced to these fundamental concepts in a dedicated lab space that allows chemistry laboratory courses to be run in the fall and spring semester. Skills obtained in the freshman laboratory course are also applied in the junior-level instrumental analysis laboratory course.