This document outlines Beer-Lambert's law, which states that the absorbance of a solution is directly proportional to the concentration of the absorbing material in the solution and the path length. It defines key terms like absorbance, transmittance, and molar absorptivity. The document also discusses factors that can cause deviations from Beer-Lambert's law at high concentrations or when impurities are present in the solution. Applications of the law include determining unknown compound concentrations and producing absorption spectra.

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2. 11/4/2015
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Introduction
Calculation
of Beer-
lambert’s
law
Conclusion
Outlines

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Lambert’s Law

5. CONT…
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7. ABSORPTION COEFFICIENT
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8. TRANSMITTANCE
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9. OPACITY OF THE MEDIUM
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Beer’s law

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BEER-LAMBERT’S LAW
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12.   (14)---log1loglog
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MOLAR ABSORPTIVITY
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13. MOLAR ABSORPTION COEFFICIENT
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14. MIXTURE
(1) If the system containing several
substances.
each substance will contributes to rate of
absorption of light.
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15. DIFFERENCE
ABSORBANCE MOLAR ABSORBANCE
 It is extensive property.
 It change with change in
conc: and thickness.
 It varies with wavelenght
of incident light.
 It is intensive property.
 It remains constant,i.e
independent of conc and
thickness of vessel.
 Its value different at
different conc.
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έ

16. VALIDITY OF BEER’S LAW
 This law is valid for solution.
 Only strictly valid for single wavelength.
 Beer-lambert’s law valid for except when high
radiation beam are employed (Lasers).
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17. TESTING BEER-LAMBERT’S LAW
 We know,
Hence for give substance at give (l)
It means law is valid for straight line when
absorbance against conc:
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ClA 
CA

18. DEVIATION IN LAW
 Presence of impurities that fluorescence or
absorb at the absorbance wavelength .
 Deviation may if monochromatic light is not
used.
 Width of silt is not proper.
 Polymerization f impurities.
 Dissociation, ionization or association of the
solute in solution.
 Presence of trace amount foreign substance
in the solution.
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19. 1
• Determination of unknown
compound by using know.
2
• Measurement of absorbance of
the compound by using
spectrophotometer.
3
• To draw absorption spectra. To
record variation by change
wavelength of incident light.
Applications
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20. CONCLUSION
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we were able to see different
amounts of absorbency using the
law’s different analyte.
The calorimeter measured the
wavelengths of the ions to produce
the absorbency value.
A reference solution was also
created to help determine the
equilibrium constant for each
solution, and also is was used to
determine how precise our results
were.

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