In part II, the students observe the same anhydride formation and decomposition of KSBA-An using IR spectroscopy. In our facility, these experiments were easily carried out using a standard attenuated total reflectance (ATR) IR spectrometer by running the reaction in a water droplet over the ATR cell surface (see Supporting Information). Deuterated water was used for this experiment to facilitate comparison to the NMR results. The students begin by scanning a D 2 O droplet on the ATR cell surface as background. A droplet of the reaction mixture can then be scanned beginning immediately after the KSBA solution is treated with EDC. A single droplet is sufficiently stable on the ATR cell to be used throughout the roughly 20 min experiment.