- You have learnt how to construct and use a standard curve to determine the concentration of an unknown solution.
- When you use a spectrophotometer, you need to know the wavelength of light your chemical of interest absorbs at.
- You need to determine the “e” value for your compound. This process of calibration is also called “creating a standard curve”. That is “standard” as in something you can measure against, and “curve” as in a function drawn on a graph.
Once you have the standard curve, you can use it in one of two ways:
- Simply read the concentration from the curve itself, by measuring the OD of the unknown and using this value to find the x value.
- Use Beer’s Law (OD = ecl) once you have determined the slope of your line on a standard curve
After completing this module you should now be able to:
- Describe the linear relationships between two parameters
- Construct and use a standard curve for determining the concentration of a unknown solution using spectroscopy
- Use Beer’s Law and the gradient of a standard curve to determine the concentration of an unknown solution using spectroscopy
If you want a printer-friendly version of this module, you can find it here in a PDF document. This printer-friendly version should be used only to review, as it does not contain any of the interactive material, and only a skeletal version of problems solved in the module.