Final answer:
The correct equation that defines the relationship between absorbance, absorptivity, path length, and concentration of a solution is: Absorbance = Absorptivity × Path Length × Concentration, according to the Beer-Lambert law.
Step-by-step explanation:
The formula that correctly defines the relationship between absorbance, absorptivity, the distance light travels through a solution (path length), and the concentration of the solution is given by Beer-Lambert law, which is Absorbance = Absorptivity × Path Length × Concentration. This relationship is commonly used in spectrophotometry to determine the concentration of a solute in solution by measuring the amount of light absorbed at a specific wavelength. It is very important in fields such as analytical chemistry and molecular biology, where precise quantification of substances is crucial.
The correct option is A: Absorbance = Absorptivity × Distance × Concentration. The term 'absorptivity' is often represented by the Greek letter epsilon (ε), 'distance' by the symbol l (path length, commonly 1 cm), and 'concentration' by c (in mol/L). Using a known absorptivity and the measured absorbance, one can calculate the concentration of the sample as demonstrated with NAD* where A260 = 1.0 and ε at 260 nm is 18,000 L* mol⁻¹*cm⁻¹, which yields a concentration of 5.6 x 10⁻² M.