biology 110

using a spectrophotometer what is the relationship between absorbance and the concentration of light absoring substance in a solution.

  1. 👍
  2. 👎
  3. 👁
  1. Absorbance is a term used by chemists. It is the log to base 10 of Io/I. where Io is the intensity of light (or infrare radiation) entering a sample and I is what comes out at a specific wavcelength. It is related to path length (cm), species concentation (moles/lieter) and a species-dependent absorption parameter in liters*mole^-1*cm^-1

    As a physicist, I was taught to use the term absorptance, which is somewhat different, I/Io. If the absorptance is A for a light beam travelling through a sample of path length L,

    A = 1 - e^(-kL), where
    k is the absorption coefficient. k is what is proportional to the concentration of the light-absorbing substance.

    In spectroscopy, the absorbance A is defined as

    1. 👍
    2. 👎
  2. You will find a more complete answer to your question at

    1. 👍
    2. 👎

Respond to this Question

First Name

Your Response

Similar Questions

  1. Physics

    A ray of light travels from substance X to substance Y. If the refracted light follows the path labeled B in the diagram, then what can be concluded about the two substances?

  2. Chemistry

    The regression line from a plot of absorbance vs. concentration yields: 𝐴 = 2.31[𝐶] + 0.002. If the absorbance of an unknown is measured to be 0.124, what is the concentration of the analyte [𝐶]?

  3. Chemistry

    When you use a spectrophotometer, should you set the wavelength of light to be the same color as that of the solution, or would a different color be more appropriate? Explain.

  4. Physics!!

    Green light is emitted when electrons in a substance make a particular energy-level transition. If blue light were instead emitted from the same substance, would it correspond to a greater or lesser change of energy in the atom?

  1. Functions/Logarithims

    Energy is needed to transport a substance from outside a living cell to inside the cell. This energy is measured in kilo calories per gram molecule, and is given by E = 1.4 log (C1) / (C2 where C1 represents the concentration of

  2. chemistry

    The standard solution of FeSCN2+ (prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN) has an absorbance of 0.510. If a trial's absorbance is measured to be 0.250 and its initial concentration of SCN–

  3. Chemistry

    A metal element (M) forms a hexadentate complex with the ligand ethylenediammine (en). Its formula is M(en)32+. The metal ion and the ligand do not absorb in the visible region of spectrophotometer and a 1.00 cm cuvette, the

  4. Chemistry (URGENT)

    In order to analyze the waste water containing Co^2+ from a manufacturing process, 1.0L of water was evaporated to 10.0mL, then placed in a spectrophotometer tube. The absorbance was found to be 0.20. Using your calibration curve,

  1. Chemistry

    How would you get the concentration(ppm) of a sample from absorbance? Absorbance of standard = 2.55 Absorbance of sample = 2.31 Wavelength of machine 345nm slit lenght = 1cm time = 2s The metal being tested is Copper and the

  2. Chemistry - Kc question

    What would happen to Kc values in an experiment if the Beer's law constance (k) value used was low ( e.g you used 4000/M when the actual constant had a value of 5000/M)? Explain your answer Absorbance = k*length cell*concentration

  3. Chem

    There are three questions in particular that I am having problems with. Here they are 1. A standard solution of FeSCN2+ is prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN. The equilibrium concentration

  4. Chemistry

    The standard solution of FeSCN2+ (prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN) has an absorbance of 0.550. If a trial's absorbance is measured to be 0.350 and its initial concentration of SCN–

You can view more similar questions or ask a new question.