What is the primary function of a spectrophotometer in a laboratory setting?

The primary function of a spectrophotometer is to measure the absorbance of light by samples. This instrument quantifies how much light at a specific wavelength is absorbed by a sample, which is critical for analyses in various types of research and laboratory work. By measuring this absorbance, researchers can infer the concentration of specific substances within a solution based on Beer-Lambert law, which states that absorbance is directly proportional to concentration. This property makes spectrophotometers essential in applications such as determining protein concentrations, assessing enzyme activity, and performing quality control in manufacturing processes.

When considering the other functions listed, measuring temperature is a separate task that requires a thermometer, mixing solutions is accomplished using different lab equipment like vortex mixers or magnetic stirrers, and visualizing molecular structures typically involves techniques such as spectroscopy or microscopy, not absorbance measurements. Thus, the focus on absorbance distinguishes the spectrophotometer as a vital analytical tool for quantitative analysis in a laboratory context.