Explains what Beer's Law and a spectrophotometer have to do with calibration curves. Describes the steps in making a calibration curve, by first making a set of standard solutions, then using a spectrophotometer to find the absorbance of each liquid, and graphing those values against their known concentrations. The curve of Beer-Lambert's Equation can then be used to find unknown concentrations of solutions. Real-world applications of calibration curves are also discussed.