Partition coefficient log p (scientific lab report) Essay

Partition coefficient logarithm p (scientific lab report) - Essay ExampleThru partition, coefficient was expressed with the concentration in the non-aqueous or lipophilic leg as the numerator. This was expressed in a formula P = Cpetroleum / Cwater. In that context, the drugs absorption tolerate be predicted victimisation the partition coefficient. In logarithmic partition, coefficient values are measured to determine the solutes hydrophocity, lipophilicity and its anent absorbability. Since body membranes are usually impermeable to foreign ionic species, except un-ionized drug molecules can partition into the membrane. Hence, the lipophilicity correlates with the state of the drug including its acidity or pH level. Note that pH levels vary in all part of the body which implies that drugs partitioned in a specific part give also have diverse un-ionized states.Partition coefficient also determines the acid dissociation constant or Ka. This can be calculated using the equation of Henderson-Hasselbalch where the product of hydrogen ion (H+) and ionized acid (A-) concentrations is divided by the concentration of unionized acid (HA). This formula is expressed with the followingKa = H+A- / HA This experiment aims to determine the different pHs and course of ionization affected the partition coefficient of salicylic acid. ... The combination such three equations would result to 1/P = 1/P + Ka/H+P of which P is partition coefficient Ka is dissociation constant CO is total concentration in oil phase and CW is total concentration in aqueous phase. Researchers will also obtain the absorbance values using different concentration of salicylic acid because this is relevant in setting a standardisation curve and a graph to reflect the concentration in the aqueous phase. Moreover, a graph plotting 1/P against the correlative of hydrogen ion concentration (1/H+) yielded a line with an intercept of 1/P and a slope of Ka/P. apply the partition coefficient and the dissoc iation constant, the pKa was calculated. Methodology This experiment comprised of two parts(a) determination of salicylate concentration to produce a calibration curveand (b) salicylate concentration measured in radicals of four different pHs. a. Salicylate Concentration Determination to evolve a Calibration Curve It aims to resolve the absorbance of salicylate solution at different concentrations to produce a calibration curve.As part of the method, researcher will use five try pipeworks. Test Tube 1 will contain 6mL of water which will be used as the blank solution to hold open the calorimeter at zero. Other test tubes will contain 5mL of water which is added to 2mL of ferric nitrate solution. Further, 1mL of different concentrations of salicylate was added to test tube 1 0.00125M for test tube 2 0.0025M for test tube 3 0.00375M for test tube 4 and 0.005M for test tube 5. With calorimeter set at a wavelength of 624nm, the absorbance of each test tube of salicylate solution wa s determined by pouring solution in cuvettes and inserting them into the calorimeter. Data