1 / 5

Determining the Concentration of a Solution: Beer’s Law

Determining the Concentration of a Solution: Beer’s Law. Chemistry 117. http:// en.wikipedia.org/wiki/File:Beer – Lambert_law_in_solution.JPG. Spectophotometry. Measures absorbance spectrum of a substance

duane
Download Presentation

Determining the Concentration of a Solution: Beer’s Law

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Determining the Concentration of a Solution: Beer’s Law Chemistry 117 http://en.wikipedia.org/wiki/File:Beer–Lambert_law_in_solution.JPG

  2. Spectophotometry • Measures absorbance spectrum of a substance • Must first measure the absorbance spectra VS wavelength. Maximum wavelength is used to calibrate and to be able to use beer’s law most effectively http://www.sarracenia.com/astronomy/remotesensing/physics050.html

  3. Absorbance • Compounds absorb UV or Visible light • 100% transmittance means no light was absorbed • 0% transmittance means all light was absorbed • Relationship between absorbance and transmittance is beer’s law

  4. Beer-Lambert Law A= εbC Where A = absorbance, ε = molar extinction coefficient, b = path length (1cm), and C = concentration. A = – Log (T) (Note 0<T<1) T = I1/I0 http://teaching.shu.ac.uk/hwb/chemistry/tutorials/molspec/beers1.htm http://en.wikipedia.org/wiki/File:Beer_lambert.png

  5. Concentration and Transmittance • Transmittance is exponentially related to the concentration of the solution • We will plot Concentration Vs Absorbance with our spectrometer • Remember- Dilution Equation: M1V1 = M2V2

More Related