Resumen de Mass Ratio of the Deuteron and Proton from the Balmer Spectrum of Hydrogen:: Variation on an Undergraduate Physical Chemistry Experiment
A common experiment in some Physical Chemistry Laboratory courses involves the analysis of the Balmer series of the hydrogen atom to derive the Rydberg constant. We describe a simple modification of this experiment, which involves a comparison of the Balmer spectrum of hydrogen and deuteron atoms to determine their nuclear mass ratio. The accuracy of the experiment relies on a sufficient amount of 1H2 being present along with 2H2 in the deuterium lamp for its use as an internal standard. In our implementation, we use a gear-driven 0.25 m scanning monochromator with a 1200 lines/mm grating. The typical precision of our measured mass ratio is better than 10 %.
