Unknown Mixture Lab Report

The purpose of this lab was to use NMR, Recrystallization, TLC, and Melting point to separate and identify the components of a given unknown mixture.

The first step of the experiment was to use the two NMR spectra given to identify the major and minor components of the unknown mixture. When an external magnetic field is applied, there is a quantized interaction between the magnetic field itself and the magnetic moment of the proton. Thus, the magnetic moment of the proton either applies with or against the magnetic field depending on direction the proton is spinning. In the alpha spin state, the magnetic moment of the proton is applied with the magnetic field, while in the beta spin state, the magnetic moment is applied against the magnetic field. A proton that is in the alpha spin state can absorb energy and flip to the higher spin state if the right amount of energy is applied. When that happens, the nucleus is in resonance with the applied magnetic field. The difference in energy between the alpha and beta spin states corresponds to a certain frequency, which can be detected by a machine when the proton moves back to the alpha state from the beta state. This frequency is plotted on an NMR spectrum. Different frequencies correspond to differences in energy between the alpha and beta …show more content…
Recrystallization is used to separate the compound of interest from any other impurities by dissolving a solid in a proper solvent. A proper solvent doesn’t dissolve the solid at room temperature but does dissolve the solid near its boiling point. It is also important that the proper solvent does dissolve impurities at room temperature but does not dissolve impurities near its boiling point. In this experiment, the crystals that were formed from recrystallization were composed of the major product and were used to find its melting point range to confirm its