CHM120H5 Lecture Notes - Lecture 1: Molar Attenuation Coefficient, Royal Aircraft Factory F.E.2, Spectrophotometry
Document Summary
Lab 1 pre-lab: according to le chatelier"s principle, the position of equilibrium will move in such a way to counteract the change. Thus, a net reaction from left to right occurs when more of a reactant is added. As increasingly more of the same reactant is added, more product will be formed. If we add so much of this reactant, then essentially all of the other reactant will be converted to product. We will use limiting quantities of fe3+ and excess amounts of scn- to produce known concentrations of fescn2+ in the solutions. The molar absorptivity constant is different for every chemical, at every wavelength. With a longer path length, the light must travel through more solution, thus hitting more molecules, and be absorbed more. This would make the absorbance increase and the solution appear darker.
