Lab Experiment: The Concept Of The Beer-Lambert Law

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In order to complete this lab in a proper manner, the concept of the beer-lambert law must be understood to ensure success in the experiment. the Beer Lambert Law compares the property of light with material through which the light is travelling.4 So, if all the light passes through a solution without any absorption, then absorbance is zero, and the percent transmitted is 100%. If all the light is absorbed, then percent transmittance is zero, and absorption is infinite.3-4 There are many forms of this equation however the formula A=Ɛlc, explains how absorbance is directly proportional to the other parameters, as long as the law is obeyed. A=Ɛlc, also tells us that absorbance depends on the quantity of the compound that is absorbed in the light …show more content…
due to this, one would not be able to get the concentration value of [Cr(NO3)3] because, one would not be able to identify how concentration and absorbance are related and applying this law to the measured absorbance of the equilibrium solution would yield the concentration of the complex. Also without knowing the beer-lambert law, one would not know the outcome of an absorbance vs concentration graph.2 The linear relationship between them is only understood, if one understands the law.

Therefore, the beer-lambert law not only explains the relationship of a solution with light, but it also explains the absorbance and concentration relationship. Without knowing this concept one, would not be able to create the absorbance vs concentration graph as one would not the direct relationship. Due to this, the calculations are needed for this lab would be either inaccurate or
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However, above a certain concentration level, the absorbance is no longer proportional to the concentration of the absorbing species, i.e. as the concentration increases, the absorbance does not increase or increases very little. Explain what caused this phenomenon and how can we avoid this error.
The beer lambert law describes the absorption behavior of solution based on low amounts of solutes dissolved in a concentration. However, when the concentration of the absorbing species is too high, the relationship between absorbance and concentration is non-linear. the reason is because5;
1. At high concentrations, the interactions with the solvent and other solute molecules change
2. At high concentrations hydrogen bonding interactions occur which interact differently with the other

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