Answer :
Final answer:
The purpose of the calibration curve in Beer's Lambert lab is to establish a relationship between absorbance and concentration, enabling the determination of the concentration of an analyte in a sample. It confirms the spectrophotometer's accuracy and the detector's linearity, and is essential for quantitative analysis in UV-Vis spectroscopy.
Therefore the correct option is b. To establish a relationship between absorbance and concentration
Explanation:
The purpose of the calibration curve in Beer's Lambert lab is to establish a relationship between absorbance and concentration. This curve is critical for determining the concentration of a molecule in an unknown solution by measuring its absorbance spectra. To construct this curve, a series of solutions with known concentrations are prepared, and the absorbance at maximum wavelength (Amax) is measured for these standards.
A Beer's law calibration curve is a plot of absorbance as a function of concentration, which theoretically should be linear and pass through the origin. If the calibration curve is linear, the equation that best fits the data is used to determine the concentration of the analyte in the sample from its absorbance. This curve also helps to verify the accuracy of the spectrophotometer and the linearity of the detector.
It is essential when employing UV-Vis spectroscopy to use a calibration curve to accurately quantify the analyte in a solution. Inaccuracies such as nonlinearity or a deviating y-intercept can indicate potential issues with sample preparation, deviations from Beer's Law, or unknown interferences in the sample.
