Question 8 options:

What is the general equation that is used to determine the concentration of any biological molecule in solution from its corrected absorbance?

Hint: An equation "equates" two entities. If you do not include two things separated by an "=", then you have not written an equation -- you will have simply written a mathematical operation.

1 answer

The general equation used to determine the concentration of a biological molecule in solution from its corrected absorbance is based on Beer's Law (also known as Beer-Lambert Law). The equation is typically written as:

\[ A = \epsilon \cdot c \cdot l \]

Where:

  • \( A \) is the corrected absorbance.
  • \( \epsilon \) is the molar absorptivity (extinction coefficient) of the molecule (in units of L/(mol·cm)).
  • \( c \) is the concentration of the molecule in solution (in units of mol/L or M).
  • \( l \) is the path length of the cuvette or sample container (in cm).

To solve for the concentration \( c \), the equation can be rearranged as:

\[ c = \frac{A}{\epsilon \cdot l} \]

This equation equates the corrected absorbance to the product of molar absorptivity and concentration times the path length, allowing you to calculate the concentration of the molecule in solution.