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UPSC Combined Geo-Scientist

Chemist

  • 3 descriptive papers
  • 200 marks each
  • 3 h per paper

Mains Paper III covers analytical and organic chemistry.

UPSC Combined Geo-Scientist, Mains · 2023 · Mains Paper III

Q5(a). Polychromatic radiation and Beer's law

Question

What are the effects of polychromatic radiation on absorbance of an analyte following Lambert-Beer's law?

Answer in brief

Beer's law holds strictly only for monochromatic light; with a band of wavelengths of unequal ε the measured absorbance is less than εbc and the A–c plot bends towards the concentration axis: negative deviation.

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Topic notes: spectroscopic instruments (Beer–Lambert law, UV–vis and IR instruments, Job's method, AAS and flame emission), with every Civil Services, IFoS and Geo-Scientist PYQ →

CoversBeer's lawpolychromatic radiationnegative deviationinstrumental deviationBeer–Lambert law

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