In the procedure for spectrophotometry, what is plotted on the x-axis of the graph created?

In the context of spectrophotometry, the x-axis of the graph typically represents the variable that is systematically varied during the analysis. In most standard spectrophotometric analyses, especially those concerning the Beer-Lambert law, the x-axis would be plotted with wavelength. This allows the analyst to observe how the absorbance of a sample changes as a function of different wavelengths of light.

While molarity can be an important factor in determining absorbance, it is generally not plotted on the x-axis in spectrophotometric graphs unless the experiment is specifically designed to illustrate the absorbance versus concentration relationship. In that case, absorbance is plotted along the y-axis and molarity on the x-axis. However, for a general spectrophotometric analysis focused on how absorbance changes with different wavelengths, wavelength is the proper choice for the x-axis.

Thus, in typical practice, the x-axis displays wavelength because it illustrates the specific points of light energy being examined for absorbance characteristics. By analyzing variations in absorbance across different wavelengths, one can derive information about the sample, such as concentration and the presence of specific molecular species.