Great professor but there are a number of scientific mistakes: 1- when you said 40 mg in 100 ml that's not 40%. The correct is 40 g in 100 ml is 40%. Gram not milligram 2- specific colour is not wavelength, each colour consists of numerous wavelengths 3- for measuring true value you need experimentally something called standard reference material or trusted colaboration
2- specific colour is not wavelength, each colour consists of numerous wavelengths'' What do you mean? For example, red is a specific colour and has a specific wavelength associated with it.
