Final answer:
The question is about calculating the concentration of a compound using UV-Vis spectroscopy, which is a technique in Chemistry. The concentration is determined by measuring the absorbance at a specific wavelength, using Beer - Lambert Law, and the known molar absorptivity of the compound.
Step-by-step explanation:
The question pertains to the field of Chemistry, specifically to the application of UV-Vis spectroscopy in analyzing the concentration of compounds such as bromide in a solution. The concept involves understanding how light absorbance, or absorbance, at a particular wavelength relates to the concentration of the compound in question through the use of the Beer - Lambert Law. To calculate the concentration, one must use the formula that considers the measured absorbance, the path length through the sample (generally 1 cm), and the molar absorptivity (or extinction coefficient, ε) of the compound at the wavelength of maximum absorption (Amax).
Molar absorptivity is a key parameter that, when combined with the absorbance and the path length, allows for the determination of the concentration of a sample. For example, the molar absorptivity of NAD* at 260 nm is given as 18,000 L*mol⁻¹*cm⁻¹. With an observed absorbance (A260) of 1.0, using the provided equation, one can calculate the concentration of NAD* in the sample. In optical spectrometry, the wavelength of maximal absorbance (Amax) is crucial, as it indicates the specific wavelength where the sample absorbs the most light, which is directly related to the compound structure and electron transition probabilities. This principle is vital in the characterization and quantification of compounds, such as determining the concentration of DNA in a sample by its absorbance at 260 nm.