CHM 2354 Lecture Notes - Lecture 13: Reference Electrode, Electrode Potential, Heparin
25 May 2015
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Chm 2354 lecture 13 potentiometry, reference, and indicator. * remember - an electric potential is generated by a separation of charge. Reference electrodes: potential chance only dependent on one cell concentration, reference electrode is fixed or saturated doesn"t change! Potentiometry the use of electrodes to measure voltages that provide chemical information. Various electrodes have been designed to respond selectively to specific analytes. Reference electrode: a half cell with a known electrode potential, eref, independent of the concentration of the analyte or any other ions in solution, always treated as the left hand electrode, eg. The observed voltage depends on the choice of reference electrodes silver-silver chloride and calomel have different potentials. Occurs whenever different electrolyte solutions are in contact. Develops at the interface aka the salt bridge. This puts a fundamental limitation on the accuracy of direct potentiometric measurements because we don"t know its contribution to the measured voltage. Sensor is selective which is a large protein (lots of .
