Question

Explain whether beer law method could or could not be used to determine the concentration of a NaCl solution.

Answer 1

Ans

Figure shows the UV-VIS spectroscopic result of NaCl solution prepared in distilled water. The solution is transparent and it absorbs in the whole visible region with increase in its concentration but the absorbance peak is found to at 540 nm. To find the concentration of unknown NaCl in solution using Beer Lambert law in which the Molar absorptivity depends on wavelength therefore should I use a white led or a LED with peak emission wavelength at 540 nm. but I have not found why the peak absorbance occurs at 540 nm.