ABSTRACT In this experiment, there were many goals. The first was to determine the wavelength of maximum absorbance for both the basic and acidic forms of Bromcresol Green (BCG). The second goal was to determine the molar extinction coefficient of BCG. The last goal was to determine the dissociation constant for BCG. Before beginning the experiment, the spectrophotometer needed to be calibrated. Setting the absorbance to 0 when there was nothing (only air) in the machine …showed first 75 words of 1217 total…

…showed last 75 words of 1217 total…The latter is the result of the [H+] plus the [B]/[HB-] The latter equation can be translated as Amix-AHB-/ AB= -Amix. Once we obtained the latter values we could now combine both and obtain the equation KBCG = [H+][B=]/[HB-] and as a consequence the value 1.8x10^-5. The value tells you the extent of dissociation of BCG. Thus, from absorbance you can obtain dissociation constants for various substances, in this case, for BCG.